0.039543 0.000000 0.000000 0.000000 0.027443 0.000000 0.000000 0.000000 0.018851 0.000000 0.000000 0.000000 Uytterhoeven, K. Van Meervelt, L. http://mmcif.pdb.org/dictionaries/ascii/mmcif_pdbx.dic 8 90.00 90.00 90.00 25.289 36.439 53.047 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 C22 H27 N9 O4 481.508 DISTAMYCIN A DISTAMYCIN; STALLIMYCIN non-polymer C10 H15 N2 O8 P 322.208 y THYMIDINE-5'-MONOPHOSPHATE DNA linking H2 O 18.015 WATER non-polymer N 1 N O N 2 N P N 3 N O N 4 N O N 5 N O N 6 N C N 7 R C N 8 N O N 9 S C N 10 N O N 11 N C N 12 R C Y 13 N N Y 14 N C Y 15 N N Y 16 N C Y 17 N C N 18 N N Y 19 N N Y 20 N C Y 21 N N Y 22 N C N 23 N H N 24 N H N 25 N H N 26 N H N 27 N H N 28 N H N 29 N H N 30 N H N 31 N H N 32 N H N 33 N H N 34 N H N 35 N H N 36 N H N 37 N O N 38 N P N 39 N O N 40 N O N 41 N O N 42 N C N 43 R C N 44 N O N 45 S C N 46 N O N 47 N C N 48 R C N 49 N N N 50 N C N 51 N O N 52 N N N 53 N C N 54 N N N 55 N C N 56 N C N 57 N H N 58 N H N 59 N H N 60 N H N 61 N H N 62 N H N 63 N H N 64 N H N 65 N H N 66 N H N 67 N H N 68 N H N 69 N H N 70 N H N 71 N O N 72 N P N 73 N O N 74 N O N 75 N O N 76 N C N 77 R C N 78 N O N 79 S C N 80 N O N 81 N C N 82 R C Y 83 N N Y 84 N C Y 85 N N Y 86 N C N 87 N C N 88 N O N 89 N N N 90 N C N 91 N N N 92 N N Y 93 N C N 94 N H N 95 N H N 96 N H N 97 N H N 98 N H N 99 N H N 100 N H N 101 N H N 102 N H N 103 N H N 104 N H N 105 N H N 106 N H N 107 N H N 108 N C N 109 N O N 110 N N Y 111 N C Y 112 N C Y 113 N C Y 114 N N Y 115 N C N 116 N C N 117 N C N 118 N O N 119 N N Y 120 N C Y 121 N C Y 122 N C Y 123 N N Y 124 N C N 125 N C N 126 N C N 127 N O N 128 N N Y 129 N C Y 130 N C Y 131 N C Y 132 N N Y 133 N C N 134 N C N 135 N C N 136 N O N 137 N N N 138 N C N 139 N C N 140 N C N 141 N N N 142 N N N 143 N H N 144 N H N 145 N H N 146 N H N 147 N H N 148 N H N 149 N H N 150 N H N 151 N H N 152 N H N 153 N H N 154 N H N 155 N H N 156 N H N 157 N H N 158 N H N 159 N H N 160 N H N 161 N H N 162 N H N 163 N H N 164 N H N 165 N H N 166 N H N 167 N H N 168 N H N 169 N H N 170 N O N 171 N P N 172 N O N 173 N O N 174 N O N 175 N C N 176 R C N 177 N O N 178 S C N 179 N O N 180 N C N 181 R C N 182 N N N 183 N C N 184 N O N 185 N N N 186 N C N 187 N O N 188 N C N 189 N C N 190 N C N 191 N H N 192 N H N 193 N H N 194 N H N 195 N H N 196 N H N 197 N H N 198 N H N 199 N H N 200 N H N 201 N H N 202 N H N 203 N H N 204 N H N 205 N H N 206 N O N 207 N H N 208 N H N 1 N sing N 2 N sing N 3 N doub N 4 N sing N 5 N sing N 6 N sing N 7 N sing N 8 N sing N 9 N sing N 10 N sing N 11 N sing N 12 N sing N 13 N sing N 14 N sing N 15 N sing N 16 N sing N 17 N sing N 18 N sing N 19 N sing N 20 N sing N 21 N sing N 22 N sing N 23 N sing Y 24 N sing Y 25 N sing Y 26 N doub N 27 N sing Y 28 N sing Y 29 N sing Y 30 N doub N 31 N sing Y 32 N doub N 33 N sing N 34 N sing Y 35 N sing Y 36 N doub N 37 N sing Y 38 N sing N 39 N sing N 40 N sing N 41 N doub N 42 N sing N 43 N sing N 44 N sing N 45 N sing N 46 N sing N 47 N sing N 48 N sing N 49 N sing N 50 N sing N 51 N sing N 52 N sing N 53 N sing N 54 N sing N 55 N sing N 56 N sing N 57 N sing N 58 N sing N 59 N sing N 60 N sing N 61 N sing N 62 N sing N 63 N sing N 64 N doub N 65 N sing N 66 N doub N 67 N sing N 68 N sing N 69 N sing N 70 N sing N 71 N doub N 72 N sing N 73 N sing N 74 N sing N 75 N sing N 76 N doub N 77 N sing N 78 N sing N 79 N sing N 80 N sing N 81 N sing N 82 N sing N 83 N sing N 84 N sing N 85 N sing N 86 N sing N 87 N sing N 88 N sing N 89 N sing N 90 N sing N 91 N sing N 92 N sing N 93 N sing N 94 N sing N 95 N sing N 96 N sing Y 97 N sing Y 98 N sing Y 99 N doub N 100 N sing Y 101 N sing N 102 N sing Y 103 N doub N 104 N doub N 105 N sing N 106 N sing N 107 N sing N 108 N sing N 109 N doub N 110 N sing N 111 N sing N 112 N sing N 113 N doub N 114 N sing N 115 N sing N 116 N sing N 117 N sing Y 118 N sing Y 119 N doub Y 120 N doub N 121 N sing Y 122 N sing N 123 N sing Y 124 N sing N 125 N sing N 126 N sing N 127 N sing N 128 N sing N 129 N sing N 130 N doub N 131 N sing N 132 N sing N 133 N sing Y 134 N sing Y 135 N doub Y 136 N doub N 137 N sing Y 138 N sing N 139 N sing Y 140 N sing N 141 N sing N 142 N sing N 143 N sing N 144 N sing N 145 N sing N 146 N doub N 147 N sing N 148 N sing N 149 N sing Y 150 N sing Y 151 N doub Y 152 N doub N 153 N sing Y 154 N sing N 155 N sing Y 156 N sing N 157 N sing N 158 N sing N 159 N sing N 160 N sing N 161 N sing N 162 N doub N 163 N sing N 164 N sing N 165 N sing N 166 N sing N 167 N sing N 168 N sing N 169 N sing N 170 N sing N 171 N sing N 172 N doub N 173 N sing N 174 N sing N 175 N sing N 176 N sing N 177 N sing N 178 N sing N 179 N doub N 180 N sing N 181 N sing N 182 N sing N 183 N sing N 184 N sing N 185 N sing N 186 N sing N 187 N sing N 188 N sing N 189 N sing N 190 N sing N 191 N sing N 192 N sing N 193 N sing N 194 N sing N 195 N sing N 196 N sing N 197 N sing N 198 N sing N 199 N sing N 200 N sing N 201 N sing N 202 N doub N 203 N sing N 204 N sing N 205 N sing N 206 N doub N 207 N sing N 208 N sing N 209 N doub N 210 N sing N 211 N sing N 212 N sing N 213 N sing N 214 N sing N 215 N sing IX Eur.J.Biochem. EJBCAI 0262 0014-2956 269 2868 2877 10.1046/j.1432-1033.2002.02952.x 12071949 Two 1 : 1 binding modes for distamycin in the minor groove of d(GGCCAATTGG). 2002 10.2210/pdb1jtl/pdb pdb_00001jtl 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 0.00000 0.00000 0.00000 100 1 IMAGE PLATE 2000-04-18 MARRESEARCH Si 111 SINGLE WAVELENGTH M x-ray 1 0.84230 1.0 BW7B EMBL/DESY, HAMBURG 0.84230 SYNCHROTRON EMBL/DESY, HAMBURG BEAMLINE BW7B 3085.029 5'-D(*GP*GP*CP*CP*AP*AP*TP*TP*GP*G)-3' 2 syn polymer 481.508 DISTAMYCIN A 1 syn non-polymer 18.015 water 74 nat water no no (DG)(DG)(DC)(DC)(DA)(DA)(DT)(DT)(DG)(DG) GGCCAATTGG A,B polydeoxyribonucleotide n n n n n n n n n n 1 1.90 35.32 VAPOR DIFFUSION, SITTING DROP 6.0 MPD, magnesium chloride, cacodylate, spermine, pH 6.0, VAPOR DIFFUSION, SITTING DROP, temperature 293K 293 MPD 1 MgCl2 1 cacodylate 1 spermine 1 5.858 1 19 A 3 B 30 -3.543 A_DC3:DG30_B 1 -17.337 0.196 -0.146 -0.243 12.069 1 19 A 4 B 29 -2.907 A_DC4:DG29_B 2 -0.687 -0.058 -0.154 -0.240 9.580 1 20 A 5 B 28 3.987 A_DA5:DT28_B 3 -14.115 0.241 0.004 -0.039 5.998 1 20 A 6 B 27 8.735 A_DA6:DT27_B 4 -23.873 0.296 0.034 0.052 -0.462 1 20 A 7 B 26 3.225 A_DT7:DA26_B 5 -20.774 -0.100 -0.048 0.016 -9.081 1 20 A 8 B 25 6.733 A_DT8:DA25_B 6 -15.772 0.051 -0.170 -0.167 -6.190 1 19 A 9 B 24 -2.883 A_DG9:DC24_B 7 -11.951 -0.193 0.016 -0.167 -2.573 1 19 A 10 B 23 -3.166 A_DG10:DC23_B 8 -16.201 -0.235 0.094 -0.117 2.847 28.345 A A 3 4 33.395 B B 30 29 3.247 15.365 0.463 0.168 AA_DC3DC4:DG29DG30_BB 1 5.880 -12.780 23.163 -3.313 0.454 3.540 48.029 A A 4 5 6.024 B B 29 28 3.446 4.895 0.287 1.119 AA_DC4DA5:DT28DG29_BB 2 0.525 -0.646 47.791 0.962 -0.309 3.286 35.904 A A 5 6 4.137 B B 28 27 3.287 2.548 -0.061 0.093 AA_DA5DA6:DT27DT28_BB 3 -0.917 1.489 35.805 -0.215 -0.034 3.279 34.247 A A 6 7 -1.712 B B 27 26 3.267 -1.008 -0.041 -0.476 AA_DA6DT7:DA26DT27_BB 4 -0.220 0.374 34.232 -0.649 0.034 3.565 40.787 A A 7 8 2.433 B B 26 25 3.495 1.693 0.777 0.321 AA_DT7DT8:DA25DA26_BB 5 4.253 -6.115 40.540 0.258 -0.608 3.118 31.372 A A 8 9 23.030 B B 25 24 3.259 12.127 -0.764 0.125 AA_DT8DG9:DC24DA25_BB 6 -2.789 5.296 28.855 -2.090 0.879 3.130 30.578 A A 9 10 10.982 B B 24 23 3.247 5.757 0.111 -0.291 AA_DG9DG10:DC23DC24_BB 7 -1.409 2.689 30.011 -1.675 -0.486 software chem_comp_atom chem_comp_bond database_2 diffrn_source struct_site pdbx_initial_refinement_model repository Initial release Version format compliance Version format compliance Refinement description Data collection Database references Derived calculations Refinement description 1 0 2002-08-09 1 1 2008-04-27 1 2 2011-07-13 1 3 2017-10-04 1 4 2024-02-07 1 5 2024-04-03 _database_2.pdbx_DOI _database_2.pdbx_database_accession _diffrn_source.pdbx_synchrotron_site _struct_site.pdbx_auth_asym_id _struct_site.pdbx_auth_comp_id _struct_site.pdbx_auth_seq_id B-DNA at Atomic resolution Reveals Extended Hydration patterns. Crystal Structure of d(GGCCAATTGG) Complexed with DAPI Reveals novel binding mode. Parallel and Antiparallel (G.GC)2 Triple Helix Fragments in a Crystal Structure. RCSB Y RCSB 2001-08-21 REL REL DMY DISTAMYCIN A HOH water This sequence is synthesized by Oswell DNA Service (Southampton, UK) sample 432D DD0002 used as starting model for refinement PDB experimental model DMY 31 2 DMY DMY 31 B HOH 101 3 HOH HOH 101 A HOH 103 3 HOH HOH 103 A HOH 104 3 HOH HOH 104 A HOH 105 3 HOH HOH 105 A HOH 112 3 HOH HOH 112 A HOH 113 3 HOH HOH 113 A HOH 114 3 HOH HOH 114 A HOH 117 3 HOH HOH 117 A HOH 118 3 HOH HOH 118 A HOH 120 3 HOH HOH 120 A HOH 121 3 HOH HOH 121 A HOH 122 3 HOH HOH 122 A HOH 123 3 HOH HOH 123 A HOH 125 3 HOH HOH 125 A HOH 126 3 HOH HOH 126 A HOH 127 3 HOH HOH 127 A HOH 128 3 HOH HOH 128 A HOH 129 3 HOH HOH 129 A HOH 131 3 HOH HOH 131 A HOH 132 3 HOH HOH 132 A HOH 133 3 HOH HOH 133 A HOH 135 3 HOH HOH 135 A HOH 136 3 HOH HOH 136 A HOH 138 3 HOH HOH 138 A HOH 139 3 HOH HOH 139 A HOH 142 3 HOH HOH 142 A HOH 160 3 HOH HOH 160 A HOH 164 3 HOH HOH 164 A HOH 165 3 HOH HOH 165 A HOH 167 3 HOH HOH 167 A HOH 173 3 HOH HOH 173 A HOH 174 3 HOH HOH 174 A HOH 102 3 HOH HOH 102 B HOH 106 3 HOH HOH 106 B HOH 107 3 HOH HOH 107 B HOH 108 3 HOH HOH 108 B HOH 109 3 HOH HOH 109 B HOH 110 3 HOH HOH 110 B HOH 111 3 HOH HOH 111 B HOH 115 3 HOH HOH 115 B HOH 116 3 HOH HOH 116 B HOH 119 3 HOH HOH 119 B HOH 124 3 HOH HOH 124 B HOH 130 3 HOH HOH 130 B HOH 134 3 HOH HOH 134 B HOH 137 3 HOH HOH 137 B HOH 140 3 HOH HOH 140 B HOH 141 3 HOH HOH 141 B HOH 143 3 HOH HOH 143 B HOH 144 3 HOH HOH 144 B HOH 145 3 HOH HOH 145 B HOH 146 3 HOH HOH 146 B HOH 147 3 HOH HOH 147 B HOH 148 3 HOH HOH 148 B HOH 149 3 HOH HOH 149 B HOH 150 3 HOH HOH 150 B HOH 151 3 HOH HOH 151 B HOH 152 3 HOH HOH 152 B HOH 153 3 HOH HOH 153 B HOH 154 3 HOH HOH 154 B HOH 155 3 HOH HOH 155 B HOH 156 3 HOH HOH 156 B HOH 157 3 HOH HOH 157 B HOH 158 3 HOH HOH 158 B HOH 159 3 HOH HOH 159 B HOH 161 3 HOH HOH 161 B HOH 162 3 HOH HOH 162 B HOH 163 3 HOH HOH 163 B HOH 166 3 HOH HOH 166 B HOH 168 3 HOH HOH 168 B HOH 169 3 HOH HOH 169 B HOH 170 3 HOH HOH 170 B HOH 171 3 HOH HOH 171 B HOH 172 3 HOH HOH 172 B G 1 n 1 DG 1 A G 2 n 2 DG 2 A C 3 n 3 DC 3 A C 4 n 4 DC 4 A A 5 n 5 DA 5 A A 6 n 6 DA 6 A T 7 n 7 DT 7 A T 8 n 8 DT 8 A G 9 n 9 DG 9 A G 10 n 10 DG 10 A G 21 n 1 DG 21 B G 22 n 2 DG 22 B C 23 n 3 DC 23 B C 24 n 4 DC 24 B A 25 n 5 DA 25 B A 26 n 6 DA 26 B T 27 n 7 DT 27 B T 28 n 8 DT 28 B G 29 n 9 DG 29 B G 30 n 10 DG 30 B author_defined_assembly 2 dimeric 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 -4.28 0.70 108.00 103.72 A A A O4' C1' N9 DG DG DG 1 1 1 N 1 -6.86 0.80 109.40 102.54 A A A O5' C5' C4' DG DG DG 2 2 2 N 1 -5.37 0.80 102.40 97.03 A A A C3' C2' C1' DC DC DC 4 4 4 N 1 3.52 0.30 108.30 111.82 A A A O4' C1' N1 DC DC DC 4 4 4 N 1 10.36 1.20 119.70 130.06 A A A C3' O3' P DC DC DA 4 4 5 Y 1 8.43 1.40 114.30 122.73 A A A N9 C1' C2' DA DA DA 5 5 5 N 1 -4.56 0.70 108.00 103.44 A A A O4' C1' N9 DA DA DA 5 5 5 N 1 -4.90 0.80 109.40 104.50 A A A O5' C5' C4' DA DA DA 6 6 6 N 1 -4.56 0.70 108.00 103.44 A A A O4' C1' N9 DA DA DA 6 6 6 N 1 -7.32 0.70 108.00 100.68 A A A O4' C1' N1 DT DT DT 7 7 7 N 1 9.56 1.40 114.30 123.86 A A A N1 C1' C2' DT DT DT 8 8 8 N 1 -8.02 0.70 108.00 99.98 A A A O4' C1' N1 DT DT DT 8 8 8 N 1 -4.34 0.60 122.90 118.56 A A A C6 C5 C7 DT DT DT 8 8 8 N 1 9.55 1.20 119.70 129.25 A A A C3' O3' P DT DT DG 8 8 9 Y 1 -5.56 0.70 108.00 102.44 A A A O4' C1' N9 DG DG DG 9 9 9 N 1 8.01 1.30 127.00 135.01 A A A C8 N9 C1' DG DG DG 10 10 10 N 1 -7.89 1.30 126.50 118.61 A A A C4 N9 C1' DG DG DG 10 10 10 N 1 2.56 0.30 108.30 110.86 B B B O4' C1' N9 DG DG DG 22 22 22 N 1 8.39 1.30 127.00 135.39 B B B C8 N9 C1' DG DG DG 22 22 22 N 1 -5.53 0.80 109.40 103.87 B B B O5' C5' C4' DA DA DA 25 25 25 N 1 -6.97 0.80 102.40 95.43 B B B C3' C2' C1' DA DA DA 25 25 25 N 1 9.46 1.20 119.70 129.16 B B B C3' O3' P DA DA DT 26 26 27 Y 1 -5.55 0.80 109.40 103.85 B B B O5' C5' C4' DT DT DT 27 27 27 N 1 -6.34 0.70 108.00 101.66 B B B O4' C1' N1 DT DT DT 27 27 27 N 1 -5.44 0.80 105.90 100.46 B B B O4' C1' C2' DT DT DT 28 28 28 N 1 -5.57 0.70 108.00 102.43 B B B O4' C1' N1 DT DT DT 28 28 28 N 1 -4.13 0.60 122.90 118.77 B B B C6 C5 C7 DT DT DT 28 28 28 N 1 -6.50 0.70 108.00 101.50 B B B O4' C1' N9 DG DG DG 29 29 29 N 1 -5.51 0.80 105.90 100.39 B B B O4' C1' C2' DG DG DG 30 30 30 N 1 A A C1' N1 DT DT 7 7 -0.102 0.014 1.468 1.366 N 1 A A C1' N1 DT DT 8 8 -0.107 0.014 1.468 1.361 N 1 B B C1' N1 DT DT 27 27 -0.111 0.014 1.468 1.357 N 1 B B C1' N1 DT DT 28 28 -0.105 0.014 1.468 1.363 N 33.99 0.2127000 0.1974000 1.85 100.0 4192 3493 83.3 1 Isotropic 4.0 MOLECULAR REPLACEMENT DD0002 used as starting model for refinement user defined 1.85 100.0 74 519 35 410 0 0.02 0.05 33.99 1.85 100.0 1JTL 4543 4223 2.5 5.0 0.0490000 1 21.08 4.3 93.0 1.85 1.92 5.1 431 0.1950000 3.9 96.9 refinement SHELXL data reduction DENZO data scaling SCALEPACK The crystal structure of d(GGCCAATTGG) Complexed with Distamycin 1 N N 1 N N 2 N N 3 N N 3 N N hydrog WATSON-CRICK A DC 3 A N3 DC 3 1_555 B DG 30 B N1 DG 10 1_555 hydrog WATSON-CRICK A DC 3 A N4 DC 3 1_555 B DG 30 B O6 DG 10 1_555 hydrog WATSON-CRICK A DC 3 A O2 DC 3 1_555 B DG 30 B N2 DG 10 1_555 hydrog WATSON-CRICK A DC 4 A N3 DC 4 1_555 B DG 29 B N1 DG 9 1_555 hydrog WATSON-CRICK A DC 4 A N4 DC 4 1_555 B DG 29 B O6 DG 9 1_555 hydrog WATSON-CRICK A DC 4 A O2 DC 4 1_555 B DG 29 B N2 DG 9 1_555 hydrog WATSON-CRICK A DA 5 A N1 DA 5 1_555 B DT 28 B N3 DT 8 1_555 hydrog WATSON-CRICK A DA 5 A N6 DA 5 1_555 B DT 28 B O4 DT 8 1_555 hydrog WATSON-CRICK A DA 6 A N1 DA 6 1_555 B DT 27 B N3 DT 7 1_555 hydrog WATSON-CRICK A DA 6 A N6 DA 6 1_555 B DT 27 B O4 DT 7 1_555 hydrog WATSON-CRICK A DT 7 A N3 DT 7 1_555 B DA 26 B N1 DA 6 1_555 hydrog WATSON-CRICK A DT 7 A O4 DT 7 1_555 B DA 26 B N6 DA 6 1_555 hydrog WATSON-CRICK A DT 8 A N3 DT 8 1_555 B DA 25 B N1 DA 5 1_555 hydrog WATSON-CRICK A DT 8 A O4 DT 8 1_555 B DA 25 B N6 DA 5 1_555 hydrog WATSON-CRICK A DG 9 A N1 DG 9 1_555 B DC 24 B N3 DC 4 1_555 hydrog WATSON-CRICK A DG 9 A N2 DG 9 1_555 B DC 24 B O2 DC 4 1_555 hydrog WATSON-CRICK A DG 9 A O6 DG 9 1_555 B DC 24 B N4 DC 4 1_555 hydrog WATSON-CRICK A DG 10 A N1 DG 10 1_555 B DC 23 B N3 DC 3 1_555 hydrog WATSON-CRICK A DG 10 A N2 DG 10 1_555 B DC 23 B O2 DC 3 1_555 hydrog WATSON-CRICK A DG 10 A O6 DG 10 1_555 B DC 23 B N4 DC 3 1_555 DNA B-DNA double helix, base triplets, minor groove binding, drug, distamycin, DNA 1JTL PDB 1 1JTL 1 10 1JTL 1 10 1JTL A 1 1 10 21 30 1JTL 21 30 1JTL B 1 1 10 BINDING SITE FOR RESIDUE DMY B 31 B DMY 31 Software 15 A DC 4 A DC 4 15 1_555 A DA 5 A DA 5 15 1_555 A DA 6 A DA 6 15 1_555 A DT 7 A DT 7 15 1_555 A DT 8 A DT 8 15 1_555 A DG 9 A DG 9 15 1_555 A HOH 126 D HOH 15 1_555 A HOH 142 D HOH 15 1_555 B DA 25 B DA 5 15 1_555 B DA 26 B DA 6 15 1_555 B DT 27 B DT 7 15 1_555 B DT 28 B DT 8 15 1_555 B DG 29 B DG 9 15 1_555 B HOH 116 E HOH 15 1_555 B HOH 153 E HOH 15 1_555 19 P 21 21 21