Table 2.
Backbone and glycosyl torsion angles
| Angle, degrees | |||||||
|---|---|---|---|---|---|---|---|
| Residue | α | β | γ | δ | ɛ | ζ | χ |
| A2 (next to intercalation) | 282 | 176 | 60 | 155 | 254 | 280 | 209 |
| A102 | 308 | 180 | 50 | 155 | 251 | 270 | 224 |
| C3 (next to intercalation) | 288 | 170 | 46 | 150 | 206 | 192 | 276 |
| C103 | 287 | 157 | 52 | 147 | 218 | 188 | 274 |
| C4 | 308 | 149 | 53 | 133 | 168 | 265 | 240 |
| C104 | 298 | 139 | 56 | 134 | 183 | 238 | 242 |
| G5 | 307 | 191 | 47 | 151 | 180 | 262 | 262 |
| G105 | 311 | 181 | 48 | 149 | 181 | 268 | 259 |
| G6 (next to intercalation) | 293 | 183 | 51 | 144 | 238 | 264 | 273 |
| G106 | 303 | 185 | 46 | 141 | 233 | 267 | 270 |
| T7 (flipped-out) | 302 | 159 | 61 | 147 | 251 | 82 | 252 |
| T107 | 281 | 184 | 69 | 161 | 254 | 74 | 258 |
| T8 (next to intercalation) | 276 | 172 | 51 | 143 | – | – | 232 |
| T108 | 236 | 184 | 81 | 130 | – | – | 221 |
| B-DNA (range) | 270–330 | 130–200 | 20–80 | 70–180 | 160–270 | 150–300 | 200–300 |
| B-DNA (mean) | 298 | 176 (I) | 48 | 128 (I) | 184 (I) | 265 (I) | 258 (A/G) |
| 146 (II) | 144 (II) | 246 (II) | 174 (II) | 241 (T/C) | |||
| 271 (II) | |||||||
Torsion angles are defined as α: O3*-P-O5*-C5*, β: P-O5*-C5*-C4*, γ: O5*-C5*-C4*-C3*, δ: C5*-C4*-C3*-O3*, ɛ: C4*-C3*-O3*-P, ζ: C3*-O3*-P-O5*, χ(Purines): O4*-C1*-N9-C4, χ(Pyrimidines): O4*-C1*-N1-C2. For the mean values BI and BII conformations are distinguished, in the case of the glycosyl torsion angle χ also purines and pyrimidines for the BI conformation.