1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 0.00000 0.00000 0.00000 Bartley, J.P. http://mmcif.pdb.org/dictionaries/ascii/mmcif_pdbx.dic 1 90.00 90.00 90.00 1.000 1.000 1.000 C10 H14 N5 O6 P 331.222 y 2'-DEOXYADENOSINE-5'-MONOPHOSPHATE DNA linking C9 H14 N3 O7 P 307.197 y 2'-DEOXYCYTIDINE-5'-MONOPHOSPHATE DNA linking C10 H14 N5 O7 P 347.221 y 2'-DEOXYGUANOSINE-5'-MONOPHOSPHATE DNA linking C10 H15 N2 O8 P 322.208 y THYMIDINE-5'-MONOPHOSPHATE DNA linking US Biochemistry BICHAW 0033 0006-2960 36 14502 14511 10.1021/bi970710q 9398169 Solution conformation of an intramolecular DNA triplex containing a nonnucleotide linker: comparison with the DNA duplex. 1997 10.2210/pdb1at4/pdb pdb_00001at4 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 0.00000 0.00000 0.00000 DI-(OCTYLPHOSPHATE) LINKER BETWEEN STRANDS 1 AND 2 AND BETWEEN STRANDS 2 AND 3. 5442.527 DNA (5'-D(*GP*AP*GP*AP*GP*AP*DOP*TP*CP*TP*CP*TP*CP*DOP*CP*TP*CP*TP*CP*T)-3') 1 syn polymer no no (DG)(DA)(DG)(DA)(DG)(DA)(DT)(DC)(DT)(DC)(DT)(DC)(DC)(DT)(DC)(DT)(DC)(DT) GAGAGATCTCTCCTCTCT A polydeoxyribonucleotide n n n n n n n n n n n n n n n n n n -15.237 1 19 A 1 A 13 -1.846 A_DG1:DC13_A 1 -8.796 -0.480 0.002 -0.241 -5.041 1 20 A 2 A 12 -3.203 A_DA2:DT12_A 2 -9.481 0.129 0.045 -0.123 6.528 1 19 A 3 A 11 -3.641 A_DG3:DC11_A 3 -13.713 -0.176 0.535 -0.233 5.967 1 20 A 4 A 10 -3.839 A_DA4:DT10_A 4 -11.046 0.078 0.128 -0.127 8.003 1 19 A 5 A 9 -2.611 A_DG5:DC9_A 5 -1.934 -0.457 0.229 -0.248 4.933 1 20 A 6 A 8 0.911 A_DA6:DT8_A 6 -12.644 0.071 -0.054 -0.129 3.190 37.767 A A 1 2 -8.064 A A 13 12 3.104 -5.195 -0.300 -1.218 AA_DG1DA2:DT12DC13_AA 1 4.053 -6.292 37.208 -1.232 0.971 2.669 34.683 A A 2 3 4.967 A A 12 11 2.806 2.948 0.388 -0.565 AA_DA2DG3:DC11DT12_AA 2 -4.932 8.308 34.218 -1.329 -1.288 3.057 35.131 A A 3 4 2.566 A A 11 10 3.116 1.548 -0.135 -1.047 AA_DG3DA4:DT10DC11_AA 3 1.881 -3.118 35.049 -1.953 0.489 2.870 31.799 A A 4 5 5.135 A A 10 9 3.003 2.806 0.180 -1.064 AA_DA4DG5:DC9DT10_AA 4 -3.028 5.542 31.537 -2.405 -0.828 2.771 33.869 A A 5 6 14.296 A A 9 8 3.171 8.244 0.713 -1.459 AA_DG5DA6:DT8DC9_AA 5 2.018 -3.500 32.818 -3.730 -0.924 database_2 pdbx_database_status pdbx_nmr_software pdbx_struct_assembly pdbx_struct_oper_list repository Initial release Version format compliance Version format compliance Data collection Database references Derived calculations Other 1 0 1998-02-18 1 1 2008-03-27 1 2 2011-07-13 1 3 2022-03-23 _database_2.pdbx_DOI _database_2.pdbx_database_accession _pdbx_database_status.process_site _pdbx_nmr_software.name ENSEMBLE OF 12 STRUCTURES Y BNL 1997-08-18 REL REL LEAST RESTRAINT VIOLATION 7 7 NOESY COSY 5.0 303 K RESTRAINED MOLECULAR DYNAMICS USING AMBER FORCEFIELD UNTIL RESIDUAL RESTRAINT ENERGY WAS LESS THAN 1 KCAL MOL-1. THE BEST 12 STRUCTURES HAD PAIRWISE RMSD OF 0.51 A. INSIGHT ALSO WAS USED. RESTRAINED MOLECULAR DYNAMICS MSI refinement Discover structure solution VNMR 600 Varian UNITY G 1 n 1 DG 1 A A 2 n 2 DA 2 A G 3 n 3 DG 3 A A 4 n 4 DA 4 A G 5 n 5 DG 5 A A 6 n 6 DA 6 A T 8 n 7 DT 8 A C 9 n 8 DC 9 A T 10 n 9 DT 10 A C 11 n 10 DC 11 A T 12 n 11 DT 12 A C 13 n 12 DC 13 A C 15 n 13 DC 15 A T 16 n 14 DT 16 A C 17 n 15 DC 17 A T 18 n 16 DT 18 A C 19 n 17 DC 19 A T 20 n 18 DT 20 A author_defined_assembly 1 monomeric 1.0000000000 0.0000000000 0.0000000000 0.0000000000 1.0000000000 0.0000000000 0.0000000000 0.0000000000 1.0000000000 1_555 x,y,z identity operation 0.0000000000 0.0000000000 0.0000000000 1 A P DT 8 A P DT 7 1 Y 1 A OP1 DT 8 A OP1 DT 7 1 Y 1 A OP2 DT 8 A OP2 DT 7 1 Y 1 A P DC 15 A P DC 13 1 Y 1 A OP1 DC 15 A OP1 DC 13 1 Y 1 A OP2 DC 15 A OP2 DC 13 1 Y 2 A P DT 8 A P DT 7 1 Y 2 A OP1 DT 8 A OP1 DT 7 1 Y 2 A OP2 DT 8 A OP2 DT 7 1 Y 2 A P DC 15 A P DC 13 1 Y 2 A OP1 DC 15 A OP1 DC 13 1 Y 2 A OP2 DC 15 A OP2 DC 13 1 Y 3 A P DT 8 A P DT 7 1 Y 3 A OP1 DT 8 A OP1 DT 7 1 Y 3 A OP2 DT 8 A OP2 DT 7 1 Y 3 A P DC 15 A P DC 13 1 Y 3 A OP1 DC 15 A OP1 DC 13 1 Y 3 A OP2 DC 15 A OP2 DC 13 1 Y 4 A P DT 8 A P DT 7 1 Y 4 A OP1 DT 8 A OP1 DT 7 1 Y 4 A OP2 DT 8 A OP2 DT 7 1 Y 4 A P DC 15 A P DC 13 1 Y 4 A OP1 DC 15 A OP1 DC 13 1 Y 4 A OP2 DC 15 A OP2 DC 13 1 Y 5 A P DT 8 A P DT 7 1 Y 5 A OP1 DT 8 A OP1 DT 7 1 Y 5 A OP2 DT 8 A OP2 DT 7 1 Y 5 A P DC 15 A P DC 13 1 Y 5 A OP1 DC 15 A OP1 DC 13 1 Y 5 A OP2 DC 15 A OP2 DC 13 1 Y 6 A P DT 8 A P DT 7 1 Y 6 A OP1 DT 8 A OP1 DT 7 1 Y 6 A OP2 DT 8 A OP2 DT 7 1 Y 6 A P DC 15 A P DC 13 1 Y 6 A OP1 DC 15 A OP1 DC 13 1 Y 6 A OP2 DC 15 A OP2 DC 13 1 Y 7 A P DT 8 A P DT 7 1 Y 7 A OP1 DT 8 A OP1 DT 7 1 Y 7 A OP2 DT 8 A OP2 DT 7 1 Y 7 A P DC 15 A P DC 13 1 Y 7 A OP1 DC 15 A OP1 DC 13 1 Y 7 A OP2 DC 15 A OP2 DC 13 1 Y 1 A DA 2 0.072 SIDE CHAIN 2 A DA 2 0.059 SIDE CHAIN 3 A DA 2 0.084 SIDE CHAIN 3 A DC 15 0.085 SIDE CHAIN 4 A DG 1 0.072 SIDE CHAIN 4 A DA 2 0.075 SIDE CHAIN 5 A DA 2 0.076 SIDE CHAIN 6 A DA 2 0.070 SIDE CHAIN 7 A DA 2 0.069 SIDE CHAIN 1 2.39 0.30 108.30 110.69 A A A O4' C1' N9 DG DG DG 1 1 1 N 1 2.52 0.30 108.30 110.82 A A A O4' C1' N9 DG DG DG 3 3 3 N 1 1.94 0.30 108.30 110.24 A A A O4' C1' N9 DA DA DA 4 4 4 N 1 2.54 0.30 108.30 110.84 A A A O4' C1' N9 DG DG DG 5 5 5 N 1 4.18 0.30 108.30 112.48 A A A O4' C1' N9 DA DA DA 6 6 6 N 1 2.19 0.30 108.30 110.49 A A A O4' C1' N1 DT DT DT 8 8 8 N 1 1.86 0.30 108.30 110.16 A A A O4' C1' N1 DC DC DC 9 9 9 N 1 2.75 0.30 108.30 111.05 A A A O4' C1' N1 DC DC DC 11 11 11 N 1 1.96 0.30 108.30 110.26 A A A O4' C1' N1 DC DC DC 13 13 13 N 1 2.07 0.30 108.30 110.37 A A A O4' C1' N1 DC DC DC 15 15 15 N 1 2.10 0.30 108.30 110.40 A A A O4' C1' N1 DT DT DT 16 16 16 N 1 2.27 0.30 108.30 110.57 A A A O4' C1' N1 DC DC DC 17 17 17 N 1 3.12 0.40 120.30 123.42 A A A C6 N1 C2 DC DC DC 17 17 17 N 1 3.18 0.50 119.90 123.08 A A A C2 N3 C4 DC DC DC 17 17 17 N 1 4.52 0.60 118.90 123.42 A A A N1 C2 O2 DC DC DC 17 17 17 N 1 2.96 0.30 108.30 111.26 A A A O4' C1' N1 DC DC DC 19 19 19 N 2 2.25 0.30 108.30 110.55 A A A O4' C1' N9 DG DG DG 1 1 1 N 2 2.88 0.30 108.30 111.18 A A A O4' C1' N9 DG DG DG 3 3 3 N 2 2.12 0.30 108.30 110.42 A A A O4' C1' N9 DA DA DA 4 4 4 N 2 2.74 0.30 108.30 111.04 A A A O4' C1' N9 DG DG DG 5 5 5 N 2 4.26 0.30 108.30 112.56 A A A O4' C1' N9 DA DA DA 6 6 6 N 2 2.11 0.30 108.30 110.41 A A A O4' C1' N1 DC DC DC 9 9 9 N 2 3.52 0.30 108.30 111.82 A A A O4' C1' N1 DC DC DC 11 11 11 N 2 2.09 0.30 108.30 110.39 A A A O4' C1' N1 DC DC DC 13 13 13 N 2 1.98 0.30 108.30 110.28 A A A O4' C1' N1 DC DC DC 15 15 15 N 2 1.94 0.30 108.30 110.24 A A A O4' C1' N1 DT DT DT 16 16 16 N 2 2.63 0.30 108.30 110.93 A A A O4' C1' N1 DC DC DC 17 17 17 N 2 3.14 0.40 120.30 123.44 A A A C6 N1 C2 DC DC DC 17 17 17 N 2 3.16 0.50 119.90 123.06 A A A C2 N3 C4 DC DC DC 17 17 17 N 2 4.62 0.60 118.90 123.52 A A A N1 C2 O2 DC DC DC 17 17 17 N 2 3.35 0.30 108.30 111.65 A A A O4' C1' N1 DC DC DC 19 19 19 N 3 2.17 0.30 108.30 110.47 A A A O4' C1' N9 DG DG DG 1 1 1 N 3 2.46 0.30 108.30 110.76 A A A O4' C1' N9 DG DG DG 3 3 3 N 3 2.56 0.30 108.30 110.86 A A A O4' C1' N9 DG DG DG 5 5 5 N 3 4.11 0.30 108.30 112.41 A A A O4' C1' N9 DA DA DA 6 6 6 N 3 2.24 0.30 108.30 110.54 A A A O4' C1' N1 DT DT DT 8 8 8 N 3 3.41 0.30 108.30 111.71 A A A O4' C1' N1 DC DC DC 11 11 11 N 3 1.91 0.30 108.30 110.21 A A A O4' C1' N1 DT DT DT 12 12 12 N 3 2.08 0.30 108.30 110.38 A A A O4' C1' N1 DC DC DC 13 13 13 N 3 5.19 0.30 108.30 113.49 A A A O4' C1' N1 DC DC DC 15 15 15 N 3 -7.84 1.20 119.70 111.86 A A A C3' O3' P DC DC DT 15 15 16 Y 3 3.95 0.30 108.30 112.25 A A A O4' C1' N1 DT DT DT 16 16 16 N 3 2.46 0.30 108.30 110.76 A A A O4' C1' N1 DC DC DC 17 17 17 N 3 3.17 0.40 120.30 123.47 A A A C6 N1 C2 DC DC DC 17 17 17 N 3 3.17 0.50 119.90 123.07 A A A C2 N3 C4 DC DC DC 17 17 17 N 3 4.53 0.60 118.90 123.43 A A A N1 C2 O2 DC DC DC 17 17 17 N 3 3.07 0.30 108.30 111.37 A A A O4' C1' N1 DC DC DC 19 19 19 N 4 4.11 0.30 108.30 112.41 A A A O4' C1' N9 DG DG DG 1 1 1 N 4 2.42 0.30 108.30 110.72 A A A O4' C1' N9 DG DG DG 3 3 3 N 4 1.91 0.30 108.30 110.21 A A A O4' C1' N9 DA DA DA 4 4 4 N 4 2.58 0.30 108.30 110.88 A A A O4' C1' N9 DG DG DG 5 5 5 N 4 4.24 0.30 108.30 112.54 A A A O4' C1' N9 DA DA DA 6 6 6 N 4 2.23 0.30 108.30 110.53 A A A O4' C1' N1 DT DT DT 8 8 8 N 4 3.41 0.30 108.30 111.71 A A A O4' C1' N1 DC DC DC 11 11 11 N 4 2.21 0.30 108.30 110.51 A A A O4' C1' N1 DC DC DC 13 13 13 N 4 4.72 0.30 108.30 113.02 A A A O4' C1' N1 DC DC DC 15 15 15 N 4 -8.08 1.20 119.70 111.62 A A A C3' O3' P DC DC DT 15 15 16 Y 4 3.93 0.30 108.30 112.23 A A A O4' C1' N1 DT DT DT 16 16 16 N 4 2.63 0.30 108.30 110.93 A A A O4' C1' N1 DC DC DC 17 17 17 N 4 3.27 0.40 120.30 123.57 A A A C6 N1 C2 DC DC DC 17 17 17 N 4 3.04 0.50 119.90 122.94 A A A C2 N3 C4 DC DC DC 17 17 17 N 4 4.51 0.60 118.90 123.41 A A A N1 C2 O2 DC DC DC 17 17 17 N 4 3.11 0.30 108.30 111.41 A A A O4' C1' N1 DC DC DC 19 19 19 N 5 2.10 0.30 108.30 110.40 A A A O4' C1' N9 DG DG DG 1 1 1 N 5 2.66 0.30 108.30 110.96 A A A O4' C1' N9 DG DG DG 3 3 3 N 5 2.50 0.30 108.30 110.80 A A A O4' C1' N9 DG DG DG 5 5 5 N 5 4.16 0.30 108.30 112.46 A A A O4' C1' N9 DA DA DA 6 6 6 N 5 2.18 0.30 108.30 110.48 A A A O4' C1' N1 DT DT DT 8 8 8 N 5 2.99 0.30 108.30 111.29 A A A O4' C1' N1 DC DC DC 11 11 11 N 5 2.13 0.30 108.30 110.43 A A A O4' C1' N1 DT DT DT 12 12 12 N 5 2.10 0.30 108.30 110.40 A A A O4' C1' N1 DC DC DC 15 15 15 N 5 2.37 0.30 108.30 110.67 A A A O4' C1' N1 DC DC DC 17 17 17 N 5 3.01 0.40 120.30 123.31 A A A C6 N1 C2 DC DC DC 17 17 17 N 5 3.19 0.50 119.90 123.09 A A A C2 N3 C4 DC DC DC 17 17 17 N 5 -2.43 0.40 121.90 119.47 A A A N3 C4 C5 DC DC DC 17 17 17 N 5 4.51 0.60 118.90 123.41 A A A N1 C2 O2 DC DC DC 17 17 17 N 5 2.83 0.30 108.30 111.13 A A A O4' C1' N1 DC DC DC 19 19 19 N 6 2.06 0.30 108.30 110.36 A A A O4' C1' N9 DG DG DG 1 1 1 N 6 2.50 0.30 108.30 110.80 A A A O4' C1' N9 DG DG DG 3 3 3 N 6 1.99 0.30 108.30 110.29 A A A O4' C1' N9 DA DA DA 4 4 4 N 6 2.51 0.30 108.30 110.81 A A A O4' C1' N9 DG DG DG 5 5 5 N 6 4.11 0.30 108.30 112.41 A A A O4' C1' N9 DA DA DA 6 6 6 N 6 2.32 0.30 108.30 110.62 A A A O4' C1' N1 DT DT DT 8 8 8 N 6 1.82 0.30 108.30 110.12 A A A O4' C1' N1 DC DC DC 9 9 9 N 6 3.48 0.30 108.30 111.78 A A A O4' C1' N1 DC DC DC 11 11 11 N 6 2.09 0.30 108.30 110.39 A A A O4' C1' N1 DC DC DC 13 13 13 N 6 1.98 0.30 108.30 110.28 A A A O4' C1' N1 DC DC DC 15 15 15 N 6 1.92 0.30 108.30 110.22 A A A O4' C1' N1 DT DT DT 16 16 16 N 6 2.28 0.30 108.30 110.58 A A A O4' C1' N1 DC DC DC 17 17 17 N 6 3.17 0.40 120.30 123.47 A A A C6 N1 C2 DC DC DC 17 17 17 N 6 3.16 0.50 119.90 123.06 A A A C2 N3 C4 DC DC DC 17 17 17 N 6 4.57 0.60 118.90 123.47 A A A N1 C2 O2 DC DC DC 17 17 17 N 6 3.08 0.30 108.30 111.38 A A A O4' C1' N1 DC DC DC 19 19 19 N 7 2.23 0.30 108.30 110.53 A A A O4' C1' N9 DG DG DG 1 1 1 N 7 2.59 0.30 108.30 110.89 A A A O4' C1' N9 DG DG DG 3 3 3 N 7 1.96 0.30 108.30 110.26 A A A O4' C1' N9 DA DA DA 4 4 4 N 7 2.53 0.30 108.30 110.83 A A A O4' C1' N9 DG DG DG 5 5 5 N 7 4.10 0.30 108.30 112.40 A A A O4' C1' N9 DA DA DA 6 6 6 N 7 2.25 0.30 108.30 110.55 A A A O4' C1' N1 DT DT DT 8 8 8 N 7 1.86 0.30 108.30 110.16 A A A O4' C1' N1 DC DC DC 9 9 9 N 7 3.50 0.30 108.30 111.80 A A A O4' C1' N1 DC DC DC 11 11 11 N 7 2.12 0.30 108.30 110.42 A A A O4' C1' N1 DC DC DC 13 13 13 N 7 1.99 0.30 108.30 110.29 A A A O4' C1' N1 DC DC DC 15 15 15 N 7 1.91 0.30 108.30 110.21 A A A O4' C1' N1 DT DT DT 16 16 16 N 7 2.32 0.30 108.30 110.62 A A A O4' C1' N1 DC DC DC 17 17 17 N 7 3.19 0.40 120.30 123.49 A A A C6 N1 C2 DC DC DC 17 17 17 N 7 3.16 0.50 119.90 123.06 A A A C2 N3 C4 DC DC DC 17 17 17 N 7 4.52 0.60 118.90 123.42 A A A N1 C2 O2 DC DC DC 17 17 17 N 7 3.15 0.30 108.30 111.45 A A A O4' C1' N1 DC DC DC 19 19 19 N 1 A A N3 C4 DC DC 17 17 0.048 0.007 1.335 1.383 N 2 A A N3 C4 DC DC 17 17 0.046 0.007 1.335 1.381 N 3 A A N3 C4 DC DC 17 17 0.047 0.007 1.335 1.382 N 4 A A N3 C4 DC DC 17 17 0.048 0.007 1.335 1.383 N 5 A A N3 C4 DC DC 17 17 0.047 0.007 1.335 1.382 N 6 A A N3 C4 DC DC 17 17 0.047 0.007 1.335 1.382 N 7 A A N3 C4 DC DC 17 17 0.047 0.007 1.335 1.382 N model building VNMR refinement AMBER phasing VNMR INTRAMOLECULAR DNA TRIPLEX CONTAINING A NON-NUCLEOTIDE LINKER (GAGAGA-X-TCTCCT-X-CTCTCT), NMR, 7 STRUCTURES 1 N N hydrog WATSON-CRICK A DG 1 A N1 DG 1 1_555 A DC 13 A N3 DC 12 1_555 hydrog WATSON-CRICK A DG 1 A N2 DG 1 1_555 A DC 13 A O2 DC 12 1_555 hydrog WATSON-CRICK A DG 1 A O6 DG 1 1_555 A DC 13 A N4 DC 12 1_555 hydrog WATSON-CRICK A DA 2 A N1 DA 2 1_555 A DT 12 A N3 DT 11 1_555 hydrog WATSON-CRICK A DA 2 A N6 DA 2 1_555 A DT 12 A O4 DT 11 1_555 hydrog HOOGSTEEN A DA 2 A N6 DA 2 1_555 A DT 16 A O4 DT 14 1_555 hydrog HOOGSTEEN A DA 2 A N7 DA 2 1_555 A DT 16 A N3 DT 14 1_555 hydrog WATSON-CRICK A DG 3 A N1 DG 3 1_555 A DC 11 A N3 DC 10 1_555 hydrog WATSON-CRICK A DG 3 A N2 DG 3 1_555 A DC 11 A O2 DC 10 1_555 hydrog WATSON-CRICK A DG 3 A O6 DG 3 1_555 A DC 11 A N4 DC 10 1_555 hydrog DG-DC PAIR A DG 3 A O6 DG 3 1_555 A DC 17 A N4 DC 15 1_555 hydrog WATSON-CRICK A DA 4 A N1 DA 4 1_555 A DT 10 A N3 DT 9 1_555 hydrog WATSON-CRICK A DA 4 A N6 DA 4 1_555 A DT 10 A O4 DT 9 1_555 hydrog HOOGSTEEN A DA 4 A N6 DA 4 1_555 A DT 18 A O4 DT 16 1_555 hydrog HOOGSTEEN A DA 4 A N7 DA 4 1_555 A DT 18 A N3 DT 16 1_555 hydrog WATSON-CRICK A DG 5 A N1 DG 5 1_555 A DC 9 A N3 DC 8 1_555 hydrog WATSON-CRICK A DG 5 A N2 DG 5 1_555 A DC 9 A O2 DC 8 1_555 hydrog WATSON-CRICK A DG 5 A O6 DG 5 1_555 A DC 9 A N4 DC 8 1_555 hydrog DG-DC PAIR A DG 5 A O6 DG 5 1_555 A DC 19 A N4 DC 17 1_555 hydrog WATSON-CRICK A DA 6 A N1 DA 6 1_555 A DT 8 A N3 DT 7 1_555 hydrog WATSON-CRICK A DA 6 A N6 DA 6 1_555 A DT 8 A O4 DT 7 1_555 hydrog HOOGSTEEN A DA 6 A N6 DA 6 1_555 A DT 20 A O4 DT 18 1_555 hydrog HOOGSTEEN A DA 6 A N7 DA 6 1_555 A DT 20 A N3 DT 18 1_555 hydrog DC-DT MISPAIR A DC 9 A N4 DC 8 1_555 A DT 18 A O4 DT 16 1_555 hydrog DT-DC MISPAIR A DT 10 A O4 DT 9 1_555 A DC 17 A N4 DC 15 1_555 hydrog DC-DT MISPAIR A DC 11 A N4 DC 10 1_555 A DT 16 A O4 DT 14 1_555 hydrog DT-DC MISPAIR A DT 12 A O4 DT 11 1_555 A DC 15 A N4 DC 13 1_555 DNA DNA, INTRAMOLECULAR TRIPLEX, DEOXYRIBONUCLEIC ACID 1AT4 PDB 1 1AT4 1 20 1AT4 1 20 1AT4 A 1 1 18 1 P 1