Table 1 Occurrence of the ten unique dinucleotide steps in the four datasets (numbers in parentheses indicate percentage occurrence).
| Â | Occurence | |||||||
|---|---|---|---|---|---|---|---|---|
| Â | RNA | Free | Complex | HTH | ||||
Dinucleotide Sequence* |  | All | A-like (Z p > 1.3 Å) | B-like (Z p ≤ 0.8 Å) | All | Excl. TEH†| All | Excl. TC ‡ |
AA/TT | 15 (5.4) | 45 (11.1) | NA | 45 (21.5) | 211 (17.2) | 126 (16.2) | 259 (16.6) | 208 (15.0) |
AG/CT | 29 (10.5) | 17 (4.2) | 3 (1.5) | 14 (6.7) | 151 (12.3) | 92 (11.8) | 138 (8.9) | 120 (8.7) |
GA/TC | 19 (6.9) | 42 (10.3) | 2 (1.0) | 40 (19.1) | 142 (11.6) | 71 (9.1) | 164 (10.5) | 151 (10.9) |
GG/CC | 36 (13.0) | 97 (23.9) | 90 (45.9) | 7 (3.3) | 120 (9.8) | 84 (10.8) | 134 (8.6) | 118 (8.5) |
AC/GT | 36 (13.0) | 23 (5.7) | 13 (6.6) | 10 (4.8) | 134 (10.9) | 98 (12.6) | 188 (12.1) | 173 (12.5) |
AT/AT | 9 (3.3) | 28 (6.9) | 4 (2.0) | 24 (11.5) | 102 (8.3) | 54 (6.9) | 155 (9.9) | 143 (10.3) |
GC/GC | 44 (15.9) | 39 (9.6) | 25 (12.8) | 13 (6.2) | 63 (5.1) | 48 (6.2) | 83 (5.3) | 71 (5.1) |
CA/TG (BI) | 43 (15.6) | 17 (4.2) | 13 (6.6) | 4 (1.9) | 93 (7.6) | 71 (9.1) | 152 (9.7) | 139 (10.0) |
CA/TG (BII) | NA | 12 (3.0) | NA | 12 (5.7) | 60 (4.9) | 57 (7.3) | 63 (4.0) | 60 (4.3) |
CG/CG | 37 (13.4) | 73 (18.0) | 43 (21.9) | 30 (14.4) | 50 (4.1) | 32 (4.1) | 82 (5.3) | 75 (5.4) |
TA/TA | 8 (3.0) | 13 (3.2) | 3 (1.5) | 10 (4.8) | 101 (8.2) | 45 (5.8) | 141 (9.0) | 126 (9.1) |
TOTAL | 276 | 406 | 196 | 209 | 1227 | 778 | 1559 | 1384 |