Beyond Intra-Base-Pair Hydrogen Bonds in DNA Structures: A Comprehensive Analysis

Jürgen Sühnel 1), Klaus Lindauer 1)
Institut für Molekulare Biotechnologie, Postfach 100813, D-07708 Jena / Germany
1) E-Mail: jsuehnel@imb-jena.de; klaus@imb-jena.de

Table II

Non-intra-base-pair hydrogen bonds in DNA structures


Base-pairs are vaguely defined as nucleotides located more or less
in one plane and connected by at least one hydrogen bond. 
This definition includes planes of three or four nucleotides occurring 
in triplex or quadruplex structures.

Hydrogen bonds within base-pairs defined in this way are intra-basepair H-bonds.

All other H-bonds are non-intra-base-pair H-bonds.

Non-intra-base-pair H-bonds may occur 

       between different base-pairs 
       or 
       between a not base-paired nucleotide and a basepair 
       or
       between two nucleotides both not belonging to base-pairs.

The set of DNA structures given below was scanned for non-intra-base-pair H-bonds
using the program HBexplore.

HBexplore identifies hydrogen bonds according to geometrical criteria.
The criteria used are:

       dHA             <       2.5 A
       dDA             <       3.9 A
       aDHA            >       90 deg
       aHAA1(2)        >       90 deg
       aDAA1(2)        >       90 deg

Here A and D stand for the acceptor an donor atoms of the H-bond.
A1(2) are the bonded neighbors of A and a and d indicate angle
and distance.

For each non-intra-base-pair H-bond identified the following information 
is given:

EXAMPLE        1dn6                    YES     
EXAMPLE
EXAMPLE                                    donor              acceptor         dDA     H-bond  type
EXAMPLE                                    at    rt    rn     at    rt    rn   
EXAMPLE        1******         15          N1    G A   9      O4    T B   2    2.7655  b-b
EXAMPLE
EXAMPLE                                    donor              acceptor         dDA         dHA       aDHA    aHAA1 aHAA2    aDAA1 aDAA2
EXAMPLE                                    at    rt    rn     at    rt    rn   
EXAMPLE                        15          N1    G A   9      O4    T B   2    2.7655      2.113     120.4   100.9 108.2  +  93.7 110.3
EXAMPLE        
EXAMPLE        H-BOND  TYPE:           G - T,  interstrand, three-center, one-H donor
EXAMPLE        MOTIF:          14          N1    G A  9      N3    C B  1    3.0920    b-b
EXAMPLE                        15          N1    G A  9      O4    T B  2    2.7655    b-b
EXAMPLE        MOTIF  TYPE:    Db3nbA(3ibA)    


The H-bonds are labeled using the HBexplore identification number.

H-BOND TYPE    describes properties of the non-intra-basepair H-bonds alone.

MOTIF          is given if a donor atom forms more than one H-bond.
MOTIF TYPE     describes the complete H-bond motif of one donor with all H-bonded acceptors
               including possibly intra-basepair H-bonds.
               It takes into account different acceptor atoms H-bonded to one and the same donor,
               but it does not take into account different donors connected to one and the same acceptor.
       
               The terminology for the MOTIF TYPE is:  
       
               i               -       intra-basepair H-bond
               n               -       non-intra-basepair H-bond
               p               -       nucleic acid-protein H-bond
               2               -       two-center (standard, can be omitted)
               3               -       three-center 
               b               -       base
               s               -       sidechain (amino acid)
               B               -       nucleic acid or protein backbone

               Examples:

               DbibA                   -       two-center intra-basepair H-bond between one donor and one acceptor
               DbnBA                   -       two-center non-intra-basepair H-bond betweem one donor base atom  and one 
                                               acceptor backbone atom
               DbpsA                   -       two-center nucleic acid-protein H-bond between one donor and one acceptor
               DbnbA(ibA)              -       one intra-basepair and one non-intra-basepair two-center H-bond between 
                                               one donor and two acceptors (requires two-H donor)
               DbnbA(nBA)              -       two non-intra-basepair H-bonds between one donor and two acceptors
               Db3nbA(3ibA)            -       three-center H-bond system where one bond is a non-intra-basepair and the other 
                                               one is an intra-basepair H-bond between one donor and two acceptors 
                                               (requires two-H donor)
               Db3nbA(3nbA)            -       three-center H-bond system where both bonds are non-intra-basepair H-bonds
                                               between one donor and two acceptors
               DbnBA(3iBA)(3ibA)       -       two-H donor forms one two-center non-intra-basepair H-bond with one hydrogen and
                                               a three-center intra-basepair H-bond with the other hydrogen
               Db3nbA(3iBA)(psA)       -       two-H donor forms one three-center non-intra-basepair H-bond and one three-center 
                                               intra-basepair H-bond with one H-atom and an nucleic acid-protein H-bond with the
                                               other hydrogen
                               
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

STRUCTURE      NON-INTRA-BASEPAIR      SEQUENCE
(PDB CODE)     H-BONDS  (YES/NO)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
A-DNA:
######                         

115d                   NO              GGXAXACC / GGXAXACC                     
137d                   NO              GCGGGCCCGC / GCGGGCCCGC
160d                   NO              CCCGGCCGGG / CCCGGCCGGG
172d                   NO              GAAGCTTC / GAAGCTTC / GAAGCTTC/ GAAGCTTC
197d                   NO              GTACGTAC / GTACGTAC
1ana                   NO              CCGG / CCGG
1d91                   NO              GGGGTCCC / GGGGTCCC
1d92                   NO              GGGGCTCC / GGGGCTCC
----------------------------------------------------------------------------------------------------------------------
1dn6                   YES             GGATGGGAG / CTCCCATCC
 1******       15          N1    G A  9      O4    T B  2    2.7655    b-b
               15          N1    G A  9      O4    T B  2    2.7655    2.113     120.4   100.9 108.2  +  93.7 110.3
 H-BOND TYPE:  G - T,  interstrand,    three-center,   one-H donor
 MOTIF:                14          N1    G A  9      N3    C B  1    3.0920    b-b
               15          N1    G A  9      O4    T B  2    2.7655    b-b
 MOTIF TYPE:   Db3nbA(3ibA)    
----------------------------------------------------------------------------------------------------------------------
218d                   NO              CGTGAATTCXCG / CGTGAATTCXCG
221d                   NO              ACCGGCCGGT / ACCGGCCGGT
2ana                   NO              GGGGCCCC / GGGGCCCC
---------------------------------------------------------------------------------------------------------------------
2d47                   YES             CCCCCGCGGGGG / CCCCCGCGGGGG
               
 2******       3           N4    C A  3      O6    G B 11    2.9681    b-b
               3           N4    C A  3      O6    G B 11    2.9681    2.307(1)  122.0   102.4 108.5  + 102.0 115.9
 H-BOND TYPE:  C - G,  interstrand,    three-center,   two-H donor
 MOTIF:                2           N4    C A  3      O6    G B 10    2.9678    b-b
               3           N4    C A  3      O6    G B 11    2.9681    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
 COMMENTS:     This is one of the rare cases of a C - G interstrand H-bond.
----------------------------------------------------------------------------------------------------------------------
3ana                   NO              GGGATCCC / GGGATCCC
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

B-DNA:
######

111d                   NO              CGCAAATTGGCG / CGCAAATTGGCG
112d                   NO              CGCGAATTAGCG / CGCGAATTAGCG
113d                   NO              CGCGAATTTGCG / CGCGAATTTGCG
114d                   NO              CGCXAATTAGCG / CGCXAATTAGCG
119d                   NO              CGTAGATCTACG / CGTAGATCTACG
122d                   NO              CCAGGCXTGG / CCAGGCXTGG
123d                   NO              CCAGGCXTGG / CCAGGCXTGG
126d                   NO              CATGGCCATG / CATGGCCATG
150d                   NO              CGCGAATTXGCG / CGCGAATTXGCG
153d                   NO              CGAGAATTCXCG / CGAGAATTCXCG
158d                   NO              CCAAGCTTGG / CCAAGCTTGG
167d                   NO              CCATTAATGG / CCATTAATGG
---------------------------------------------------------------------------------------------------------------------
178d                   YES             CGCAAATTXGCG / CGCAAATTXGCG
       
 3******       5           N6    A A  5      O4    T B 19    2.7425    b-b
               5           N6    A A  5      O4    T B 19    2.7425    2.447(2)   96.0   105.0 110.9  + 124.9 132.0
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                6           N6    A A  5      O4    T B 19    2.7425    b-b
               7           N6    A A  5      O4    T B 20    2.7081    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
----------------------------------------------------------------------------------------------------------------------
194d                   NO              CGCGTTAACGCG / CGCGTTAACGCG
196d                   NO              CTCTCGAGAG / CTCTCGAGAG
1bdnA                  NO              CGCAAAAATGCG / CGCATTTTTGCG             (two structures in one PDB file)
----------------------------------------------------------------------------------------------------------------------
1bdnC                  YES             CGCAAAAATGCG / CGCATTTTTGCG             (two structures in one PDB file)

 4******       7           N6    A C  6      O4    T D  6    2.8095    b-b
               7           N6    A C  6      O4    T D  6    2.810     2.455(2)  99.8  118.3 110.6 136.3 130.9
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                7           N6    A C  6      O4    T D  6    2.8095    b-b
               8           N6    A C  6      O4    T D  7    2.4826    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
----------------------------------------------------------------------------------------------------------------------                 
1bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG
1cgc                   NO              CCGGCGCCGG / CCGGCGCCGG
1d23                   NO              CGATCGATCG / CGATCGATCG
1d27                   NO              CGCXAATTTGCG / CGCXAATTTGCG
1d28                   NO              CGTGAATTCACG / CGTGAATTCACG
1d29                   NO              CGTGAATTCACG / CGTGAATTCACG
1d49                   NO              CGATTAATCG / CGATTAATCG
1d56                   NO              CGATATATCG / CGATATATCG
1d57                   NO              CGATATATCG / CGATATATCG
1d60                   NO              CCAACXTTGG / CCAACXTTGG
1d65                   NO              CGCAAATTTGCG / CGCAAATTTGCG                     
1d75                   NO              CGCGAATTXGCG / CGCGAATTXGCG
1d77                   NO              CGCXAATTCGCG / CGCXAATTCGCG
1d80                   NO              CGCGAATTGGCG / CGCGAATTGGCG
1d81                   NO              CGCAAATTXGCG / CGCAAATTXGCG
-----------------------------------------------------------------------------------------------------------------------
1d89                   YES             CGCGAAAAAACG / CGTTTTTTCGCG
                                       CGCGAAAAAACG / CGTTTTTTCGCG
                                       CGCGAAAAAACG / CGTTTTTTCGCG
       
 5******       15          N6    A A 10      O6    G B 14    2.7774    b-b
               15          N6    A A 10      O6    G B 14    2.7774    2.499(2)   95.1   105.6 104.0  + 121.0 124.7
 H-BOND TYPE:  A - G,  interstrand,    three-center,   two-H donor
 MOTIF:                15          N6    A A 10      O6    G B 14    2.7774    b-b
               16          N6    A A 10      O4    T B 15    3.1486    b-b
 MOTIF TYPE:   Db3nbA(3ibA)

 6******       44          N6    A C107      O4    T D117    2.9314    b-b
               44          N6    A C107      O4    T D117    2.9314    2.490(2)  105.8   107.2 105.0  + 125.0 124.1
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                44          N6    A C107      O4    T D117    2.9314    b-b
               45          N6    A C107      O4    T D118    2.8968    b-b
 MOTIF TYPE:   Db3nbA(3ibA)

 7******       78          N6    A E209      O4    T F215    2.9410    b-b
               78          N6    A E209      O4    T F215    2.9410    2.499(2)  105.9   102.7 110.5  + 119.0 129.8
 H-BOND TYPE:  A - T   interstrand,    three-center,   two-H donor
 MOTIF:                78          N6    A E209      O4    T F215    2.9410    b-b
               79          N6    A E209      O4    T F216    2.9278    b-b
 MOTIF TYPE:   Db3nbA(3ibA)

 8******       80          N6    A E210      O6    G F214    2.6745    b-b
               80          N6    A E210      O6    G F214    2.6745    2.425(2)   92.9   115.8 109.6  + 131.4 131.4
 H-BOND TYPE:  A - G,  interstrand,    three-center,   two-H donor
 MOTIF:                80          N6    A E210      O6    G F214    2.6745    b-b
               81          N6    A E210      O4    T F215    3.2010    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
-----------------------------------------------------------------------------------------------------------------------
1d97                   NO              GXGXGX / GXGXGX
1d98                   NO              CGCAAAAAAGCG / CGCTTTTTTGCG     (Nelson, Klug paper !!!! Nature 1987, 330, 221-226)
------------------------------------------------------------------------------------------------------------------------
1d99                   YES             CGCAAATTCGCG / CGCAAATTCGCG
       
 9******       14          N2    G A 10      O2    C A 11    3.0539    b-b
               14          N2    G A 10      O2    C A 11    3.0539    2.459(1)  117.1   108.6 113.1  + 102.4 116.6
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                13          N1    G A 10      N3    C B 15    2.7699    b-b
               14          N2    G A 10      O2    C A 11    3.0539    b-b
               15          N2    G A 10      O2    C B 15    2.6801    b-b
 MOTIF TYPE:   DbnbA(3ibA)(3ibA)
 COMMENTS:     One H of the amine group forms two base-pair H-bonds,
                       the other H forms one non-intra-basepair H-bond.
------------------------------------------------------------------------------------------------------------------------
1da3                   NO              CGATCGXTCG / CGATCGXTCG
------------------------------------------------------------------------------------------------------------------------
1dn9                   YES             CGCATATATGCG / CGCATATATGCG
       
 10*****       20          N4    C B  3      O4    T A  9    2.9083    b-b
               20          N4    C B  3      O4    T A  9    2.9083    2.449(1)  106.9   117.3 112.1  + 135.3 130.9
 H-BOND TYPE:  C - T,  interstrand,    three-center,   two-H donor
 MOTIF:                20          N4    C B  3      O4    T A  9    2.9083    b-b
               21          N4    C B  3      O6    G A 10    2.7916    b-b
 MOTIF TYPE:   Db3nbA(3ibA)

 11*****       11          N2    G A 10      O2    C A 11    2.8379    b-b
               11          N2    G A 10      O2    C A 11    2.8379    2.322(1)  110.5   104.8 102.6  + 101.3 109.9
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                11          N2    G A 10      O2    C A 11    2.8379    b-b
               12          N2    G A 10      O2    C B  3    2.6560    b-b
 MOTIF TYPE:   DbnbA(ibA)
 COMMENTS:     One H of the amine group forms one base-pair H-bond,
                       the other H forms one non-intra-basepair H-bond
------------------------------------------------------------------------------------------------------------------------
1dnm                   YES             CGCAAGCTGGCG / CGCAAGCTGGCG
       
 12*****       6           N6    A A  4      O4    T B 20    2.8948    b-b
               6           N6    A A  4      O4    T B 20    2.8948    2.349(2)  112.9    96.2 101.5  +  95.0 109.4
 H-BOND TYPE:  A - T,  interstrand,    two-center,     two-H donor
 MOTIF:                6           N6    A A  4      O4    T B 20    2.8948    b-b
               7           N6    A A  4      O6    G B 21    2.6764    b-b
 MOTIF TYPE:   DbnbA(ibA)      

 13*****       23          N4    C B 15      O6    G A  9    2.8152    b-b
               23          N4    C B 15      O6    G A  9    2.8152    2.132(1)  123.2   123.7 125.1  + 138.9 142.2
 H-BOND TYPE:  C - G,  interstrand,    three-center,   two-H donor
 MOTIF:                23          N4    C B 15      O6    G A  9    2.8152    b-b
               24          N4    C B 15      O6    G A 10    2.9058    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
 COMMENTS:     This is one of the rare cases of a C - G interstrand H-bond.
               It occurs between the C of a G-C pair and the G of a G-A pair
------------------------------------------------------------------------------------------------------------------------
1ndnA                  YES             CGCGAAAACGCG / CGCGTT / TTCGCG  (two structures in one PDB file)
       
 14*****       23          N2    G B 16      N3    G A 10    2.9531    b-b
               23          N2    G B 16      N3    G A 10    2.953     2.409(2) 113.0  100.9  90.4 119.2  82.0
 H-BOND TYPE:  G - G,  interstrand,    three-center,   two-H donor
 MOTIF:                22          N2    G B 16      O2    C A  9    2.9806    b-b
               23          N2    G B 16      N3    G A 10    2.9531    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
------------------------------------------------------------------------------------------------------------------------
1ndnT                  YES             CGCGAAAACGCG / CGCGTT / TTCGCG  (two structures in one PDB file)

 15*****       26          N3    T V 19      N1    A T  7    2.6342    b-b
               26          N3    T V 19      N1    A T  7    2.634     2.217    102.9   87.2 110.3 107.9 103.6
 H-BOND TYPE:  T - A,  interstrand,    three-center,   two-H donor
 MOTIF:                25          N3    T V 19      N1    A T  6    2.9221    b-b
               26          N3    T V 19      N1    A T  7    2.6342    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
------------------------------------------------------------------------------------------------------------------------
2bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG
2d25                   NO              CCAGGCXTGG / CCAGGCXTGG
3bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG
------------------------------------------------------------------------------------------------------------------------
4bna                   YES             CGCGAATTCGCG / CGCGAATTCGCG
       
 16*****       15          N2    G A 10      O2    C A 11    3.1394    b-b
               15          N2    G A 10      O2    C A 11    3.1394    2.458(1)  124.3    97.4 108.9  +  91.5 110.7
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                15          N2    G A 10      O2    C A 11    3.1394    b-b
               16          N2    G A 10      O2    C B  3    2.7757    b-b
 MOTIF TYPE:   DbnbA(ibA)
-----------------------------------------------------------------------------------------------------------------------
4dnb                   NO              CGCGAXTTCGCG / CGCGAXTTCGCG             
7bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG
9bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Z-DNA:
######

131d                   NO              CGCGCG / CGCGCG
133d                   NO              CGCGXG / CGCGXG
145d_AB                        NO              XGGGXG / XGCCXG         (two structures in one PDB file)
145d_CD                        NO              XGCCXG / XGGGXG         (two structures in one PDB file)
180d                   NO              CGCACG / CGTGCG
181d                   NO              CACGCG / CGCGTG
1d24                   NO              CGCXCG / CGCXCG
1d39                   NO              CGCGCG / CGCXCG
1d40                   NO              XGUAXG / XGUAXG
1d41                   NO              XGUAXG / XGUAXG
1d48                   NO              CGCGCG / CGCGCG
1d53                   NO              CG / CG / CGCG / CGCG
1d76                   NO              CGUXCG / CGUXCG
1da1                   NO              XGCGCG / XGCGCG
1da2                   NO              CGCGXG / CGCGXG
1dcg                   NO              CGCGCG / CGCGCG
1dn4                   NO              XGXGXG / XGXGXG
1dn5                   NO              XGXGXG / XGXGXG
1dn8                   NO              TG / TG
1dnf                   NO              CGCGUG / CGCGUG
1zna                   NO              CGCG / CGCG
223d                   NO              CGCGXG / CGCGXG
2dcg                   NO              CGCGCG / CGCGCG

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Other DNA:
#########

190d                   NO              CCCC / CCCC / CCCC / CCCC / CCCC / CCCC / CCCC / CCCC
191d                   NO              CCCT / CCCT / CCCT / CCCT
192d                   NO              CCGCGG / CCGCGG
1d16                   NO              CGCGCGTTTTCGCGCG 
-------------------------------------------------------------------------------------------------------------------
1d31                   YES             CGCAGAATTCGCG / CGCAGAATTCGCG

 17*****       39          N1    G B 26      O1P   C B 25    2.5711    b-B
               39          N1    G B 26      O1P   C B 25    2.571     2.072    108.1  149.1 161.1 127.6 149.2
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     one-H donor
 MOTIF TYPE:   DbnBA
-------------------------------------------------------------------------------------------------------------------
1d59                   NO              GGGGTTTTGG / GGGGTTTTGG / GGGGTTTTGG / GGGGTTTTGG       (tetraplex)
-------------------------------------------------------------------------------------------------------------------
200d                   YES             TAACCC / TAACCC

 18*****       5           N4    C A  4      O1P   A A  3    2.7537    b-B
               5           N4    C A  4      O1P   A A  3    2.754     1.817(2) 152.7  152.0 148.2 143.6 147.7
 H-BOND TYPE:  C - A,  intrastrand,    two-center,     two-H donor
 MOTIF:                5           N4    C A  4      O1P   A A  3    2.7537    b-B
               6           N4    C A  4      O2    C B 14    2.5998    b-b
 MOTIF TYPE:   DbnBA(ibA)              

 19*****       15          N4    C B 14      O2P   A B 13    2.5444    b-B
               15          N4    C B 14      O2P   A B 13    2.544     1.552(2) 166.1  137.2 116.0 139.4 120.2
 H-BOND TYPE:  C - A,  intrastrand,    two-center,     two-H donor
 MOTIF:                14          N4    C B 14      O2    C A  4    2.8180    b-b
               15          N4    C B 14      O2P   A B 13    2.5444    b-B
 MOTIF TYPE:   DbnBA(ibA)
-------------------------------------------------------------------------------------------------------------------
208d                   NO              GCGAATTCG / GCGAATTCG
241d                   NO              CCCAAT / CCCAAT

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

DRUG-DNA:
#########

101d                   NO              CGCGAATTXGCG / CGCGAATTXGCG                     
102d                   NO              CGCAAATTTGCG / CGCAAATTTGCG
109d                   NO              CGCGAATTCGCG / CGCGAATTCGCG
---------------------------------------------------------------------------------------------------------------------
121d                   YES             CGCAAATTTGCG / CGCAAATTTGCG

 20*****       5           N6    A A  4      O4    T B 20    3.0525    b-b
               5           N6    A A  4      O4    T B 20    3.0525    2.498(2)  114.1   108.9 108.3  + 123.2 125.8
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor     
 MOTIF:                5           N6    A A  4      O4    T B 20    3.0525    b-b
               6           N6    A A  4      O4    T B 21    2.9019    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
       
 21*****       7           N6    A A  5      O4    T B 19    2.8954    b-b
               7           N6    A A  5      O4    T B 19    2.8954    2.342(2)  113.4   124.2 120.5  + 142.0 137.8
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                7           N6    A A  5      O4    T B 19    2.8954    b-b
               8           N6    A A  5      O4    T B 20    2.8715    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
----------------------------------------------------------------------------------------------------------------------
127d                   NO              CGCGAATTCGCG / CGCGAATTCGCG
128d                   NO              CGCXAATTCGCG / CGCXAATTCGCG     
129d                   NO              CGCGAATTCGCG / CGCGAATTCGCG
130d                   NO              CGCXAATTCGCG / CGCXAATTCGCG                     
144d                   NO              CGCXAATTCGCG / CGCXAATTCGCG             
154d                   NO              XGCG / XGCG
166d                   NO              CGCGAATTCGCG / CGCGAATTCGCG
182d                   NO              TGATCA / TGATCA
195d                   NO              CGCGTTAACGCG / CGCGTTAACGCG
198d                   NO              CGATCG / CGATCG / CGATCG / CGATCG
1d21                   NO              XGTXXG / XGTXXG
1d22                   NO              XGTXXG / XGTXXG
1d30                   NO              CGCGAATTCCCG / CGCGAATTCCCG
1d32                   NO              CGCG / CGCG
----------------------------------------------------------------------------------------------------------------------
1d43                   YES             CGCGAATTCGCG / CGCGAATTCGCG

 22*****       15          N2    G A 10      O2    C A 11    3.1846    b-b
               15          N2    G A 10      O2    C A 11    3.1846    2.469(1)  127.4   104.8 115.7  +  99.6 117.8
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                15          N2    G A 10      O2    C A 11    3.1846    b-b
               16          N2    G A 10      O2    C B 15    2.7238    b-b
 MOTIF TYPE:   DbnbA(ibA)
----------------------------------------------------------------------------------------------------------------------
1d44                   YES             CGCGAATTCGCG / CGCGAATTCGCG

 23*****       13          N2    G A 10      O2    C A 11    3.1585    b-b
               13          N2    G A 10      O2    C A 11    3.1585    2.447(1)  126.9   102.7 113.1  +  98.5 116.4
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                14          N2    G A 10      O2    C A 11    3.1585    b-b
               15          N2    G A 10      O2    C B 15    2.8490    b-b
 MOTIF TYPE:   DbnbA(ibA)
----------------------------------------------------------------------------------------------------------------------
1d45                   NO              CGCGAATTCGCG / CGCGAATTCGCG
---------------------------------------------------------------------------------------------------------------------
1d46                   YES             CGCGAATTCGCG / CGCGAATTCGCG

 24*****       7           N6    A A  5      O4    T B 19    2.9397    b-b
               7           N6    A A  5      O4    T B 19    2.9397    2.381(2)  113.9   111.3 122.9  + 127.1 141.1
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                7           N6    A A  5      O4    T B 19    2.9397    b-b
               8           N6    A A  5      O4    T B 20    3.2941    b-b
 MOTIF TYPE:   Db3nbA(3ibA)    
----------------------------------------------------------------------------------------------------------------------
1d63                   NO              CGCAAATTTGCG / CGCAAATTTGCG
1d64                   NO              CGCGAATTCGCG / CGCGAATTCGCG
1d86                   NO              CGCGAATTCGCG / CGCGAATTCGCG
1dne1                  NO              CGCGATATCGCG / CGCGATATCGCG     
1dnh                   NO              CGCGAATTCGCG / CGCGAATTCGCG
1gpg                   NO              CCXCTXXTCTCC / GGAGACCAGAGG / CCXCTXXTCTCC / GGAGACCAGAGG
1lex                   NO              CGCGAATTCGCG / CGCGAATTCGCG
1ley                   NO              CGCGAATTCGCG / CGCGAATTCGCG
1prp                   NO              CGCGAATTCGCG / CGCGAATTCGCG
209d                   NO              GAAGCTTC / GAAGCTTC
224d                   NO              TGATCA / TGATCA
227d                   NO              CGCGAATTCGCG / CGCGAATTCGCG     
---------------------------------------------------------------------------------------------------------------------
264d                   YES             CGCAAATTTGCG / CGCAAATTTGCG
       
 25*****       13          N2    G A 10      O2    C A 11    3.0526    b-b
               13          N2    G A 10      O2    C A 11    3.0526    2.481(1)  115.3   104.2 111.0  +  97.8 113.4
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                13          N2    G A 10      O2    C A 11    3.0526    b-b
               14          N2    G A 10      O2    C B 15    2.6006    b-b
 MOTIF TYPE:   DbnbA(ibA)
----------------------------------------------------------------------------------------------------------------------
2d55                   NO              GAAGCTTC / GAAGCTTC
2dbe                   NO              CGCGAATTCGCG / CGCGAATTCGCG
2des                   NO              CGTACG / CGTACG
----------------------------------------------------------------------------------------------------------------------
2dnd                   YES             CGCAAATTTGCG / CGCAAATTTGCG
       
 26*****       6           N6    A A  5      O4    T B  7    2.7074    b-b
               6           N6    A A  5      O4    T B  7    2.7074    2.148(2)  113.0   121.6 121.7  + 140.6 140.3
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                6           N6    A A  5      O4    T B  7    2.7074    b-b
               7           N6    A A  5      O4    T B  8    2.8949    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
----------------------------------------------------------------------------------------------------------------------
5bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG
6bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG
8bna                   NO              CGCGAATTCGCG / CGCGAATTCGCG

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

PROTEIN-DNA:
############
1apl                   NO              ACATGTAACATTTACACGC / TGCGTGTAAATGAATTACATG
1brn                   NO              CGAC / CGAC 
----------------------------------------------------------------------------------------------------------------------
cd
                       YES             GTCACACTTTTCGGCGAAAAGTGTGACATAT / GTCACACTTTTCGGCGAAAAGTGTGACATAT

 27*****       452         N6    A D 21      O4    T D 10    2.9910    b-b
               452         N6    A D 21      O4    T D 10    2.991     2.441(2) 113.5  116.7 119.6 132.6 137.5
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor     
 MOTIF:                452         N6    A D 21      O4    T D 10    2.9910    b-b
               453         N6    A D 21      O4    T D 11    2.7856    b-b
 MOTIF TYPE:   Db3nbA(3ibA)

 28*****       457         N2    G D 23      O2    T D 10    2.6710    b-b
               457         N2    G D 23      O2    T D 10    2.671     2.468(1)  90.3  110.3 100.8  93.3  93.2
 H-BOND TYPE:  G - T,  interstrand,    two-center,     two-H donor
 MOTIF:                456         N2    G D 23      O2    C D  9    2.7367    b-b
               457         N2    G D 23      O2    T D 10    2.6710    b-b
 MOTIF TYPE:   DbnbA(ibA)                                                                      
----------------------------------------------------------------------------------------------------------------------
1cma                   NO              TTAGACGTCT / AGACGTCTA
----------------------------------------------------------------------------------------------------------------------
1d66                   YES             CCGGAGGACAGTCCTCCGG / CCGGAGGACTGTCCTCCGG

 29*****       49          N2    G E 30      O4*   T E 31    2.9561    b-B
               49          N2    G E 30      O4*   T E 31    2.956     2.199(1) 130.5   97.9 137.4  91.8 151.3
 H-BOND TYPE:  G - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                48          N2    G E 30      O2    C D  9    2.7774    b-b
               49          N2    G E 30      O4*   T E 31    2.9561    b-B
 MOTIF TYPE:   DbnBA(ibA)
----------------------------------------------------------------------------------------------------------------------
1dct                   YES             ACCAGCAGGXCACCAGTG / TCACTGGTGGXCTGCTGG / ACCAGCAGGXCACCAGTG / ACCAGCAGGXCACCAGTG

 30*****       35          N2    G M  9      O4*   A F 12    3.1569    b-B
               35          N2    G M  9      O4*   A F 12    3.157     2.348(2) 136.4  112.5 128.7 102.9 129.9
 H-BOND TYPE:  G - A,  interstrand,    two-center.     two-H donor
 MOTIF TYPE:   DbnBA
 COMMENTS:     Only one H of N2 is involved in an H-bond. Other atoms of G M 9 form H-bonds with 
               an amino acid.

 31*****       33          N2    G N  9      O4*   A G 12    3.2031    b-B
               33          N2    G N  9      O4*   A G 12    3.203     2.396(2) 136.3  112.3 128.0 102.8 129.3
 H-BOND TYPE:  G - A,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnBA
 COMMENTS:     Only one H of N2 is involved in an H-bond. Other atoms of G N 9 form H-bonds with 
               an amino acid.
---------------------------------------------------------------------------------------------------------------------
1dnk                   NO              GGTATAC / GGTATACC 
1glu                   NO              CCAGAACATCGATGTTCTG / CCAGAACATCGATGTTCTG
---------------------------------------------------------------------------------------------------------------------
1hcr                   YES             TGTTTTTGATAAGA / TCTTATCAAAAAC

 32*****       57          N2    G B  3      O4    T B  2    2.7222    b-b
               57          N2    G B  3      O4    T B  2    2.722     1.959(1) 130.2   99.6 127.9 115.3 143.5
 H-BOND TYPE:  G - T,  intrastrand,    two-center,     two-H donor     
 MOTIF:                57          N2    G B  3      O4    T B  2    2.7222    b-b
               58          N2    G B  3      O2    C C 29    2.5676    b-b
 MOTIF TYPE:   DbnbA(ibA)
 COMMENTS:     T2 is last nucleotide in strand B

 33*****       84          N6    A C 26      O4    T B  5    2.8834    b-b
               84          N6    A C 26      O4    T B  5    2.883     2.404(1) 108.1  108.6 120.9  90.7 108.4
 H-BOND TYPE:  A - T,  interstrand,    two-center,     two-H donor
 MOTIF:                84          N6    A C 26      O4    T B  5    2.8834    b-b
               85          N6    A C 26      O4    T B  6    2.7098    b-b
 MOTIF TYPE:   DbnbA(ibA)
---------------------------------------------------------------------------------------------------------------------
1hdd                   NO              TTTTGCCATGTAATTACCTAA / ATTAGGTAATTACATGGCAAA
1hut                   NO              GGTTGGTGTGGTTGG         (single-stranded quadruplex)
                               
---------------------------------------------------------------------------------------------------------------------
1kln                   YES             GCCTCGCGGCGGCGCCGCGAGGC (single stranded double helix with missing nucleotides 1, 15-18)

 34*****       553         N2    G B  2      O4*   C B  3    3.0779    b-B
               553         N2    G B  2      O4*   C B  3    3.078     2.405(1) 123.4  111.6 133.1 101.4 148.3
 H-BOND TYPE:  G - C,  intrastrand,    two-center,     two-H donor
 MOTIF:                553         N2    G B  2      O4*   C B  3    3.0779    b-B
               554         N2    G B  2      O2    C B 29    3.4722    b-b
 MOTIF TYPE:   DbnBA(ibA)
---------------------------------------------------------------------------------------------------------------------
1lli                   YES             AATACCACTGGCGGTGATAT / TATATCACCGCCAGTGGTAT

 35*****       228         N6    A D  1      O4    T E 20    3.0092    b-b     
               228         N6    A D  1      O4    T E 20    3.009     2.345(2) 122.4   99.6 102.9  97.5 108.8
 H-BOND TYPE:  A - T,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnbA
 COMMENTS:     Only one H of N6 is involved in a H-bond. However A1 is last single nucleotide in 
               strand D.
---------------------------------------------------------------------------------------------------------------------
1lmb                   YES             AATACCACTGGCGGTGATAT / TATATCACCGCCAGTGGTAT

 36*****       1           N6    A 1  1      O4    T 2 40    3.0777    b-b
               1           N6    A 1  1      O4    T 2 40    3.078     2.481(2) 117.3   95.0  99.0  93.4 105.8
 H-BOND TYPE:  A - T,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnbA
 COMMENTS:     Only one H of N6 is involved in a H-bond. However, A1 is last single nucleotide in 
               strand 1.
---------------------------------------------------------------------------------------------------------------------
1mdy                   YES             TCAACAGCTGTTGA / TCAACAGCTGTTGA / TCAACAGCTGTTGA / TCAACAGCTGTTGA

 37*****       285         N4    C E  5      O4    T F  9    2.7753    b-b
               285         N4    C E  5      O4    T F  9    2.775     2.241(1) 111.5  126.2 125.7 145.7 141.8
 H-BOND TYPE:  C - T,  interstrand,    three-center,   two-H donor
 MOTIF:                284         N4    C E  5      OE1 GLU A118    3.1039    b-s
               285         N4    C E  5      O4    T F  9    2.7753    b-b
               286         N4    C E  5      O6    G F 10    3.3227    b-b
 MOTIF TYPE:   Db3nbA(3ibA)(psA)
 COMMENTS:     Interesting motif: One H of N4 forms a three-center H-bond with T F 9 and G F 10,
               the other H forms a two-center H-bond with GLU A 118.

 38*****       307         N4    C F  5      O4    T E  9    2.7083    b-b
               307         N4    C F  5      O4    T E  9    2.708     2.223(1) 107.8  125.5 125.2 146.1 142.1
 H-BOND TYPE:  C - T,  interstrand,    three-center,   two-H donor
 MOTIF:                306         N4    C F  5      OE1 GLU B118    2.9687    b-s
               307         N4    C F  5      O4    T E  9    2.7083    b-b
               308         N4    C F  5      O6    G E 10    3.2557    b-b
 MOTIF TYPE:   Db3nbA(3ibA)(psA)
 COMMENTS:     Interesting motif: like above.

 39*****       328         N4    C G  5      O4    T H  9    2.8043    b-b
               328         N4    C G  5      O4    T H  9    2.804     2.340(1) 106.8  121.2 122.3 141.2 139.3
 H-BOND TYPE:  C - T,  interstrand,    three-center,   two-H donor
 MOTIF:                328         N4    C G  5      O4    T H  9    2.8043    b-b
               329         N4    C G  5      O6    G H 10    3.3032    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
 COMMENTS:     Iteresting motif: like above, the H-bond to GLU C 118 is not identified because 
               the H...A distance is slightly above the limit of 2.5 A

 40*****       345         N4    C H  5      O4    T G  9    2.7816    b-b
               345         N4    C H  5      O4    T G  9    2.782     2.315(1) 106.9  120.2 121.9 140.3 139.4
 H-BOND TYPE:  C - T,  interstrand,    three-center,   two-H donor
 MOTIF:                345         N4    C H  5      O4    T G  9    2.7816    b-b
               346         N4    C H  5      O6    G G 10    3.2528    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
 COMMENTS:     Interesting motif: like above, the H-bond to GLU D 118 is not identified because 
               the H...A distance is slightly above the limit of 2.5 A.
--------------------------------------------------------------------------------------------------------------------
1oct                   NO              TGTATGCAAATAAGG / ACCTTATTTGCATAC
1par                   NO              TATAGTAGAGTGCTTCTATCAT / AATGATAGAAGCACTCTACTAT
--------------------------------------------------------------------------------------------------------------------
1per                   YES             AAGTACAGTTTTTCTTGTAT / TATACAAGAAAAACTGTACT

 41*****       37          N6    A B 12      O4    T A  9    2.8232    b-b
               37          N6    A B 12      O4    T A  9    2.823     2.393(2) 104.6  107.4 107.4 126.7 126.8
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                37          N6    A B 12      O4    T A  9    2.8232    b-b
               38          N6    A B 12      O4    T A 10    2.6969    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
--------------------------------------------------------------------------------------------------------------------
1pdn                   NO              AACGTCACGGTTGAC / TTGTCAACCGTGACG
1pvi                   NO              TGACCAGCTGGTC / TGACCAGCTGGTC
1pyi                   NO              TCGGCAATTGCCGA / TCGGCAATTGCCGA
1rpe                   NO              GACAAACAAGATACATTGTAT / TATACAATGTATCTTGTTT
--------------------------------------------------------------------------------------------------------------------
1rva                   YES             AAAGATATCTT / AAAGATATCTT

 42*****       624         N6    A C  7      O4    T C  6    3.0492    b-b
               624         N6    A C  7      O4    T C  6    3.049     2.277(1) 132.2  114.4 111.5 115.9 120.5
 H-BOND TYPE:  A - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                624         N6    A C  7      O4    T C  6    3.0492    b-b
               625         N6    A C  7      O4    T D  6    2.9498    b-b
 MOTIF TYPE:   DbnbA(ibA)

 43*****       641         N6    A D  7      O4    T D  6    2.9757    b-b
               641         N6    A D  7      O4    T D  6    2.976     2.263(1) 126.4  115.5 109.9 117.9 120.5
 H-BOND TYPE:  A - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                640         N6    A D  7      O4    T C  6    3.0138    b-b
               641         N6    A D  7      O4    T D  6    2.9757    b-b
 MOTIF TYPE:   DbnbA(ibA)
---------------------------------------------------------------------------------------------------------------------
1rvb                   YES             AAAGATATCTT / AAAGATATCTT

 44*****       597         N6    A D  7      O4    T D  6    2.9506    b-b
               597         N6    A D  7      O4    T D  6    2.951     2.151(1) 134.8  118.6 112.9 120.7 122.3
 H-BOND TYPE:  A - T   intrastrand,    two-center,     two-H donor
 MOTIF:                596         N6    A D  7      O4    T C  6    3.0284    b-b
               597         N6    A D  7      O4    T D  6    2.9506    b-b
 MOTIF TYPE:           DbnbA(ibA)

 45*****       579         N6    A C  7      O4    T C  6    3.0036    b-b
               579         N6    A C  7      O4    T C  6    3.004     2.173(1) 138.4  121.7 118.1 120.9 124.5
 H-BOND TYPE:  A - T   intrastrand,    two-center,     two-H donor
 MOTIF:                579         N6    A C  7      O4    T C  6    3.0036    b-b
               596         N6    A D  7      O4    T C  6    3.0284    b-b
 MOTIF TYPE:   DbnbA(ibA)
--------------------------------------------------------------------------------------------------------------------
1rvc                   YES             AAAGAT / ATCTT / AAAGAT / ATCTT

 46*****       601         N6    A D  7      O4    T C  6    3.1279    b-b
               601         N6    A D  7      O4    T C  6    3.128     2.274(1) 141.5  104.4 103.7 113.1 115.2
 H-BOND TYPE:  A - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                601         N6    A D  7      O4    T C  6    3.1279    b-b
               602         N6    A D  7      O4    T E  6    3.1704    b-b
 MOTIF TYPE:   DbnbA(ibA)
 COMMENTS:     The second H-bond like for 1rva and rvb is slightly longer than tolerated by the 
               geometrical criteria.
---------------------------------------------------------------------------------------------------------------------
1tro                   NO              TGTACTAGTTAACTAGTAC / TGTACTAGTTAACTAGTAC / TGTACTAGTTAACTAGTAC
                                       TGTACTAGTTAACTAGTAC
--------------------------------------------------------------------------------------------------------------------
1ysa                   YES             TTCCTATGACTCATCCAGTT / AAACTGGATGAGTCATAGGA

 47*****       25          N4    C B 24      N7    A B 23    3.1813    b-b
               25          N4    C B 24      N7    A B 23    3.181     2.208(2) 161.3   87.9 164.6  87.3 159.9
 H-BOND TYPE:  C - A,  intrastrand,    two-center,     two-H donor
 MOTIF:                24          N4    C B 24      O6    G A 18    2.6330    b-b
               25          N4    C B 24      N7    A B 23    3.1813    b-b     
 MOTIF TYPE:   DbnbA(ibA)

 48*****       46          N2    G B 38      O4*   G B 39    3.0860    b-B
               46          N2    G B 38      O4*   G B 39    3.086     2.473(1) 118.6  136.5 118.5 120.3 133.4
 H-BOND TYPE:  G - G,  intrastrand,    two-center,     two-H donor
 MOTIF:                45          N2    G B 38      O2    C A  4    3.0978    b-b
               46          N2    G B 38      O4*   G B 39    3.0860    b-B
 MOTIF TYPE:   DbnBA(ibA)
---------------------------------------------------------------------------------------------------------------------
1ytb                   YES             GTATATAAAACGGGTGGCGTTTTATATAC / GTATATAAAACGGGTGGCGTTTTATATAC

 49*****       437         N6    A C  3      O4    T C  2    2.8788    b-b
               437         N6    A C  3      O4    T C  2    2.879     2.098(1) 132.6  117.2 112.5 119.2 122.4
 H-BOND TYPE:  A - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                437         N6    A C  3      O4    T C  2    2.8788    b-b
               438         N6    A C  3      O4    T C 27    3.0593    b-b
 MOTIF TYPE:   DbnBA(ibA)

 50*****       456         N1    G C 16      O3*   G C 13    3.1937    b-B
               456         N1    G C 16      O3*   G C 13    3.194     2.217    162.4   92.3 146.2  97.6 140.7
 H-BOND TYPE:  G - G,  intrastrand,    three-center,   one-H donor
 MOTIF:                456         N1    G C 16      O3*   G C 13    3.1937    b-B
               457         N1    G C 16      O2P   G C 14    3.0688    b-B
               Db3nBA(3nBA)    (!!!!   see below)

 51*****       457         N1    G C 16      O2P   G C 14    3.0688    b-B
               457         N1    G C 16      O2P   G C 14    3.069     2.313    130.7   91.8 113.4 106.1 127.3
 H-BOND TYPE:  G - G,  intrastrand,    three-center,   one-H donor
 MOTIF:                456         N1    G C 16      O3*   G C 13    3.1937    b-B
               457         N1    G C 16      O2P   G C 14    3.0688    b-B
 MOTIF TYPE:   Db3nBA(3nBA)    (!!!    see below)
 COMMENTS:     This bond and the previous bond are the only three-center bonds (?),
               where both are of the  non-inter-basepair type. This means that they belong the 
               same motif.

 52*****       458         N2    G C 16      O2P   G C 14    2.7920    b-B
               458         N2    G C 16      O2P   G C 14    2.792     1.980(2) 135.6  126.1 116.8 136.1 131.3
 H-BOND TYPE:  G - G,  intrastrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnBA
 COMMENTS:     The three last bonds are intrastrand within a loop (no neighbours).
               The last two non-intra-basepair H-bonds are formed between two different donors
               and one and the same acceptor.

 53*****       480         N6    A D  3      O4    T D  2    2.8148    b-b
               480         N6    A D  3      O4    T D  2    2.815    2.096(1) 126.4  117.5 110.6 120.4 122.3
 H-BOND TYPE:  A - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                480         N6    A D  3      O4    T D  2    2.8148    b-b
               515         N6    A D 28      O4    T D  2    2.9571    b-b
 MOTIF TYPE:   DbnbA(ibA)

 54*****       497         N1    G D 16      O3*   G D 13    3.2429    b-B
               497         N1    G D 16      O3*   G D 13    3.243     2.315    152.1   85.1 152.5  93.5 144.3
 H-BOND TYPE:  G - G,  intrastrand,    two-center,     one-H donor     
 MOTIF:                497         N1    G D 16      O3*   G D 13    3.2429    b-B
               498         N1    G D 16      O2P   G D 14    2.8957    b-B
 MOTIF TYPE:   Db3nBA(3nBA)    (!!!!   see below)

 55*****       498         N1    G D 16      O2P   G D 14    2.8957    b-B
               498         N1    G D 16      O2P   G D 14    2.896     2.059    138.8   96.6 118.9 109.9 131.5
 H-BOND TYPE:  G - G,  intrastrand,    two-center,     one-H donor
 MOTIF:                497         N1    G D 16      O3*   G D 13    3.2429    b-B
               498         N1    G D 16      O2P   G D 14    2.8957    b-B
 MOTIF TYPE:   Db3nBA(3nBA)    (!!!!   see above)

 56*****       499         N2    G D 16      O2P   G D 14    2.7476    b-B
               499         N2    G D 16      O2P   G D 14    2.748     1.872(2) 143.1  143.8 128.2 147.4 139.5
 H-BOND TYPE:  G - G,  intrastrand,    two-center,     two-H donor
 MOTIF:                498         N1    G D 16      O2P   G D 14    2.8957    b-B
               499         N2    G D 16      O2P   G D 14    2.7476    b-B
 MOTIF TYPE:   DbnBA
 COMMENTS:     Strand D shows the same characteristics like C described above.
---------------------------------------------------------------------------------------------------------------------
1zaa                   NO              AGCGTGGGCGT / TACGCCCACGC
2bpf                   NO              CGGCGCC / GGGCGCCG
---------------------------------------------------------------------------------------------------------------------
2bpg                   YES             CGGCGCC / GGGCGCCG / CGGCGCC / GGGCGCCG / CGGCGCC / GGGCGCCG

 57*****       626         N4    C C  9      O6    G D  2    2.6083    b-b
               626         N4    C C  9      O6    G D  2    2.608     2.050(1) 112.4  110.2 111.6 128.4 132.6
 H-BOND TYPE:  C - G,  interstrand,    two-center,     two-H donor
 MOTIF:                626         N4    C C  9      O6    G D  2    2.6083    b-b
               627         N4    C C  9      O6    G D  3    2.3479    b-b
 MOTIF TYPE:   DbnbA(ibA)
 COMMENTS:     This is one of the rare cases of a C - G interstrand H-bond.
---------------------------------------------------------------------------------------------------------------------
2dnj                   NO              GCGATCGC / GCGATC
2drp                   NO              CTAATAAGGATAACGTCCG / TCGGACGTTATCCTTATTA
---------------------------------------------------------------------------------------------------------------------
2or1                   YES             AAGTACAAACTTTCTTGTAT / TATACAAGAAAGTTTGTACT

 58*****       1           N6    A A  1      O4    T B 20    2.9727    b-b        
               1           N6    A A  1      O4    T B 20    2.973     2.223(2) 129.9  139.0 127.8 150.2 142.9
 H-BOND TYPE:  A - T,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnbA
 COMMENTS:     First nucleotide in a strand.

 59*****       16          N3    T A 13      N1    A B 10    3.1322    b-b
               16          N3    T A 13      N1    A B 10    3.132     2.347    133.8  132.2  77.8 144.2  77.3
 H-BOND TYPE:  T - A,  interstrand,    two-center,     one-H donor
 MOTIF TYPE:   DbnbA
 COMMENTS:     Not an end nucleotide.
----------------------------------------------------------------------------------------------------------------------
2rve                   NO              CGAGCTCG / CGAGCTCG / CGAGCTCG / CGAGCTCG
----------------------------------------------------------------------------------------------------------------------
3cro                   YES             AAGTACAAACTTTCTTGTAT / TATACAAGAAAGTTTGTACT
 
 60*****       1           N6    A A  1      O4    T B 20    2.4299    b-b
               1           N6    A A  1      O4    T B 20    2.430     2.024(2) 101.1  102.5  95.8 125.9 118.6
 H-BOND TYPE:  A - T,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnbA
 COMMENTS:     A1 is a single nucleotide at the end of a strand.
----------------------------------------------------------------------------------------------------------------------

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

DNA-NMR:

175d                   NO              GCGAATGAGC / GCGAATGAGC
---------------------------------------------------------------------------------------------------------------------
107d                   YES             CCTTTTC / GAAAAGG

 61*****       12          N6    A B 11      O4    T A  3    3.1007    b-b
               12          N4    C A 10      O6    G B 11    2.927     1.974(1) 156.3  139.1 167.2 134.4 162.1
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                12          N6    A B 11      O4    T A  3    3.1007    b-b
               13          N6    A B 11      O4    T A  4    3.1151    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
---------------------------------------------------------------------------------------------------------------------
108d                   YES             CGCTAGCG / CGCTAGCG

 62*****       1           N4    C A  1      O6    G A  2    3.0728    b-b
               1           N4    C A  1      O6    G A  2    3.073     2.351(1) 127.5  110.6 100.4 112.0  95.
 H-BOND TYPE:  C - G,  intrastrand,    three-center,   two-H donor
 MOTIF:                1           N4    C A  1      O6    G A  2    3.0728    b-b
               2           N4    C A  1      O6    G B  8    2.8355    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
--------------------------------------------------------------------------------------------------------------------
146d                   NO              TCGCGA / TCGCGA
--------------------------------------------------------------------------------------------------------------------
185d                   YES             GACGTC / GACGTC

 63*****       14          N3    T C 15      O6    G D 17    2.7661    b-b
               14          N3    T C 15      O6    G D 17    2.766     2.021    128.6  125.6 130.8 141.1 146.5
 H-BOND TYPE:  T - G,  interstrand,    three-center,   one-H donor
 MOTIF:                14          N3    T C 15      O6    G D 17    2.7661    b-b
               15          N3    T C 15      N1    A D 18    2.6398    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
-------------------------------------------------------------------------------------------------------------------
193d                   NO              ACACGTGT / ACACGTGT
199d                   NO              XCACGTCXT / ACGACGTGC
202d                   NO              GACATGTC / GACATGTC
1gat                   NO              AGATAAACGTTTATCT        (duplex)
1gau                   NO              AGATAAACGTTTATCT        (duplex)
1mse                   NO              CCTAACTGACACACAT / ATGTGTGTCAGTTAGG
1msf                   NO              CCTAACTGACACACAT / ATGTGTGTCAGTTAGG
-------------------------------------------------------------------------------------------------------------------
103d                   YES             GTGGAATGGAAC / GTGGAATGGAAC

 64*****       30          N6    A B 22      O2    T A  2    2.8928    b-b
               30          N6    A B 22      O2    T A  2    2.893     2.341(2) 113.3  115.8 124.0 103.7 120.8
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                30          N6    A B 22      O2    T A  2    2.8928    b-b
               31          N6    A B 22      O4*   G A  3    3.0124    b-B
 MOTIF TYPE:   Db3nbA(3iBA)
 COMMENTS:     The intra-basepair H-bond is a little bit unusual (backbone). 
               This is due to the fact that the planes of the bases B22 and A3 
               are twisted. Nevertheless, we consider them as a basepair.
               In addition to the H-bond mentioned there are further intra-basepair
               H-bonds between B22 and A3.

 65****                5           N2    G A  4      O2P   A B 22    2.8234    b-B
               5           N2    G A  4      O2P   A B 22    2.823     1.833(1) 166.0  152.8 151.5 150.7 154.9
 H-BOND TYPE:  G - A,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnBA

 66*****       6           N6    A A  5      O2    T B 19    2.9653    b-b
               6           N6    A A  5      O2    T B 19    2.965     2.338(2) 119.2  112.4 122.8 100.8 118.9
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                6           N6    A A  5      O2    T B 19    2.9653    b-b
               7           N6    A A  5      O4*   G B 20    3.0139    b-B
               8           N6    A A  5      N3    G B 20    2.8697    b-b
 MOTIF TYPE:   Db3nbA(3iBA)(ibA)
 COMMENTS:     The second H not involved in the three-center bond forms another H-bond.

 67*****       29          N2    G B 21      O2P   A A  5    2.8039    b-B
               29          N2    G B 21      O2P   A A  5    2.804     1.811(1) 166.9  152.5 156.3 150.1 159.5
 H-BOND TYPE:  G - A,  interstrand,    three-center,   two-H donor
               29          N2    G B 21      O2P   A A  5    2.8039    b-B
 MOTIF TYPE:   DbnBA

 68*****       23          N6    A B 17      O2    T A  7    2.9721    b-b
               23          N6    A B 17      O2    T A  7    2.972     2.341(2) 119.6  112.3 122.8 100.8 118.9
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                23          N6    A B 17      O2    T A  7    2.9721    b-b
               24          N6    A B 17      O4*   G A  8    3.0166    b-B
               25          N6    A B 17      N3    G A  8    2.8698    b-b
 MOTIF TYPE:   Db3nbA(3iBA)(ibA)
 COMMENTS:     Same motif as above.

 69*****       13          N6    A A 10      O2    T B 14    2.8980    b-b
               13          N6    A A 10      O2    T B 14    2.898     2.337(2) 114.0  115.8 124.3 103.7 121.1
 H-BOND TYPE:  A - T,  interstrand,    three-center,   two-H donor
 MOTIF:                13          N6    A A 10      O2    T B 14    2.8980    b-b
               14          N6    A A 10      O4*   G B 15    3.0165    b-B
               15          N6    A A 10      N3    G B 15    2.8790    b-b
 MOTIF TYPE:   Db3nbA(3iBA)(ibA)
 COMMENTS:     Same motif as above.

 70****                22          N2    G B 16      O2P   A A 10    2.8205    b-B
               22          N2    G B 16      O2P   A A 10    2.820     1.828(1) 166.6  153.4 152.8 151.0 155.9
 H-BOND TYPE:  G - A,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnBA

 71*****       12          N2    G A  9      O2P   A B 17    2.8029    b-B
               12          N2    G A  9      O2P   A B 17    2.803     1.808(1) 167.5  152.8 157.6 150.1 160.5
 H-BOND TYPE:  G - A,  interstrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnBA
------------------------------------------------------------------------------------------------------------------
105d                   NO              TCC / TCC / TCC / TCC                   (quadruplex)
106d                   NO              XCT / XCT / XCT / XCT                   (quadruplex)
134d                   NO              TCCTCCTTTTTTAGGAGGATTTTTTGGTGGT         (triplex)
136d                   NO              TCCTCCTTTTTAGGAGGATTTTTTGGTGG           (triplex)
139d                   NO              TTGGGGT / TTGGGGT / TTGGGGT / TTGGGGT(quadruplex)
-----------------------------------------------------------------------------------------------------------------
143d                   YES             AGGGTTAGGGTTAGGGTTAGGG          (quadruplex)


 72*****       8           N6    A    7      O2    T   18    2.4236    b-b
               8           N6    A    7      O2    T   18    2.424     1.425(1) 168.5  109.8 119.9 110.8 118.3
 H-BOND TYPE:  A - T,  intrastrand,    two-center,     two-H donor
 MOTIF:                8           N6    A    7      O2    T   18    2.4236    b-b
               9           N6    A    7      O4*   A   19    2.8890    b-B
 MOTIF TYPE:   DbnbA(nBA)

 73*****       9           N6    A    7      O4*   A   19    2.8890    b-B
               9           N6    A    7      O4*   A   19    2.889     1.920(2) 159.9  129.8 116.4 125.9 122.2
 H-BOND TYPE:  A - A,  intrastrand,    two-center,     two-H donor
 MOTIF:                8           N6    A    7      O2    T   18    2.4236    b-b
               9           N6    A    7      O4*   A   19    2.8890    b-B
 MOTIF TYPE:   DbnBA(nbA)
 COMMENTS:     The two non-intra-basepair bonds belong to the same motif. A two-H donor forms with 
               his two different hydrogens two two-center non-intra-base-pair H-bonds.

------------------------------------------------------------------------------------------------------------------
149d                   NO              CCTATTCGAATAGGCTTGTCC           (triplex)
156d                   NO              GGGGTTTTGGGG / GGGGTTTTGGGG     (quadruplex)
177d                   NO              GAACAGGTTTTTCCTGTTCTTTTTXTTTTXX (triplex)
----------------------------------------------------------------------------------------------------------------
179d                   YES             TCGA / TCGA

 74*****       1           N3    T A  1      O4*   C B  6    2.8491    b-B
               1           N3    T A  1      O4*   C B  6    2.849     1.843    173.6  127.1 100.4 128.3 101.3
 H-BOND TYPE:  T - C,  interstrand,    two-center,     one-H donor
 MOTIF TYPE:   DbnBA

 75*****       6           N3    T B  5      O4*   C A  2    2.8416    b-B
               6           N3    T B  5      O4*   C A  2    2.842     1.855    164.7  117.8 108.2 122.9 106.8
 H-BOND TYPE:  T - C,  interstrand,    two-center,     one-H donor
 MOTIF TYPE:   DbnBA
----------------------------------------------------------------------------------------------------------------
186d                   YES             TTGGGGTTGGGGTTGGGGTTGGGG        (quadruplex)

 76*****       1           N3    T    2      O4    T   14    2.9324    b-b
               1           N3    T    2      O4    T   14    2.932     2.232    125.2  133.3 108.9 146.9 119.4
 H-BOND TYPE:  T - T,  intrastrand,    three-center,   one-H donor
 MOTIF:                1           N3    T    2      O4    T   14    2.9324    b-b
               2           N3    T    2      O6    G   15    2.8788    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
       
 77*****       8           N2    G    5      O3*   G    6    2.9379    b-B
               8           N2    G    5      O3*   G    6    2.938     2.368(1) 114.7   93.1 112.6 105.6 113.3
 H-BOND TYPE:  G - G,  intrastrand,    two-center,     two-H donor
 MOTIF:        8           N2    G    5      O3*   G    6    2.9379    b-B
               9           N2    G    5      N7    G   10    2.8982    b-b
 MOTIF TYPE:   DbnBA(ibA)

 78*****       10          N2    G    6      O4*   T    7    2.7799    b-B
               10          N2    G    6      O4*   T    7    2.780     1.826(1) 156.2  137.9 110.8 131.1 115.6
 H-BOND TYPE:  G - T,  intrastrand,    two-center,     two-H donor
 MOTIF TYPE:   DbnBA

 79*****       12          N2    G    9      O1P   T    8    2.6473    b-B
               12          N2    G    9      O1P   T    8    2.647     1.686(1) 157.5  129.6 142.6 121.3 135.9
 H-BOND TYPE:  G - T,  intrastrand,    three-center,   two-H donor
 MOTIF:                12          N2    G    9      O1P   T    8    2.6473    b-B
               13          N2    G    9      O6    G   10    2.7695    b-b
               14          N2    G    9      O6    G   24    2.7000    b-b
 MOTIF TYPE:   Db3nBA(3nbA)(ibA)
 COMMENTS:     Two non-intra-basepair H-bonds are involved in a three-center bond.

 80*****       13          N2    G    9      O6    G   10    2.7695    b-b
               13          N2    G    9      O6    G   10    2.769     2.467(1)  96.5  100.0  92.5 115.4 113.0
 H-BOND TYPE:  G - G   intrastrand,    three-center,   two-H donor
 MOTIF:                12          N2    G    9      O1P   T    8    2.6473    b-B
               13          N2    G    9      O6    G   10    2.7695    b-b
               14          N2    G    9      O6    G   24    2.7000    b-b
 MOTIF TYPE:   Db3nbA(3nBA)(ibA)
 COMMENTS:     Two non-intra-basepair H-bonds are involved in a three-center bond.     

 81*****       11          N1    G    9      O6    G   23    2.8318    b-b
               11          N1    G    9      O6    G   23    2.832     2.496     98.8   99.7  98.7 118.4 110.9
 H-BOND TYPE:  G - G   intrastrand,    two-center,     one-H donor
 MOTIF TYPE:   DbnbA
----------------------------------------------------------------------------------------------------------------
1d18                   NO              CATGCATG / CATGCATG
1d19                   NO              GTACGTAC / GTACGTAC
1d20                   NO              TCTATCACCG / CGGTGATAGA
1d70                   NO              GTATAATG / CATTATAC
-----------------------------------------------------------------------------------------------------------------
1da4                   YES             CTCTAGTGCTCAC / GTGAGCACTAGAG

 82*****       12          N6    A A 12      O6    G B 14    2.8693    b-b
               12          N6    A A 12      O6    G B 14    2.869     2.427(2) 105.6  105.9 106.7 121.6 126.4
 H-BOND TYPE:  A - G,  interstrand,    three-center,   two-H donor
 MOTIF:                12          N6    A A 12      O6    G B 14    2.8693    b-b
               13          N6    A A 12      O4    T B 15    2.9245    b-b
 MOTIF TYPE:   Db3nbA(3ibA)
-----------------------------------------------------------------------------------------------------------------
201d                   NO              GGGGTTTTGGGGTTTTGGGGTTTTGGGG            (quadruplex)
-----------------------------------------------------------------------------------------------------------------