1 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 GGAUCGCAUU UGGACUUCUG CC Crystallography ? ? Angstroms 1 G O3' 12.804 -1.540 26.196 2 G P 12.091 -1.018 27.524 O3' 12.837 -2.700 32.497 3 A P 11.759 -1.824 33.272 O3' 12.532 -0.098 37.657 4 U P 11.415 0.917 38.168 O3' 11.352 5.033 40.989 5 C P 9.852 5.590 40.930 O3' 8.694 10.649 40.927 6 G P 7.256 10.066 41.372 O3' 4.265 14.028 38.900 7 C P 5.295 15.220 39.163 O3' 8.411 17.920 35.338 8 A P 8.251 19.383 35.954 O3' 2.744 20.992 37.072 9 U P 3.416 22.446 37.204 O3' 0.271 21.498 41.203 10 U P 0.472 19.902 41.470 O3' -4.244 16.866 39.127 11 U P -5.277 17.805 38.308 O3' -5.220 15.419 32.701 12 G P -5.289 16.358 31.401 O3' -0.434 19.956 31.222 13 G P -0.153 21.310 30.442 O3' 0.295 19.287 26.276 14 A P -1.137 18.804 26.837 O3' -2.802 15.943 22.928 15 C P -4.129 15.298 23.581 O3' -5.554 11.257 21.000 16 U P -7.009 10.703 21.381 O3' -9.250 7.412 25.485 17 U P -10.355 6.311 25.181 O3' -8.855 0.394 26.351 18 C P -8.923 -0.108 24.823 O3' -2.994 -0.559 25.216 19 U P -2.860 -1.928 26.034 O3' -0.202 -2.673 30.563 20 G P 0.368 -3.913 31.370 O3' 2.016 -6.548 35.492 21 C P 2.280 -8.128 35.323 O3' 1.383 -12.159 38.539 22 C P 2.146 -13.300 37.682 O3' -0.226 -17.861 37.938 12 syn 18 syn 6 13 W H c 16 18 ! ! ! 10 11 ! ! ! 18 19 ! ! ! SG1 1 1 SG2 6 12 SG3 16 18 1 497.082 0.000 2 497.082 14.636 3 497.082 39.029 4 497.082 63.423 5 497.082 87.816 6 497.082 112.210 7 497.082 160.996 8 497.082 185.390 9 497.082 209.783 10 497.082 234.177 11 497.082 258.570 12 497.082 282.963 13 497.082 307.357 14 497.082 331.750 15 497.082 356.144 16 497.082 370.780 17 497.082 385.416 18 497.082 400.052 19 96.087 519.087 20 83.206 498.371 21 70.326 477.656 22 57.445 456.940 1 18 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 CGGCACCA CGGUCGGAUC Crystallography ? ? Angstroms 1 C O3' -10.136 -14.452 23.744 2 G P -10.791 -13.174 24.449 O3' -12.611 -15.524 29.042 3 G P -13.262 -14.304 29.851 O3' -13.116 -14.729 34.954 4 C P -13.898 -13.391 35.373 O3' -12.348 -10.410 39.362 5 A P -13.405 -9.233 39.053 O3' -10.955 -4.561 40.720 6 C P -12.490 -4.086 40.681 O3' -11.347 0.904 39.274 7 C P -11.457 2.480 39.020 O3' -9.596 6.499 38.421 8 A P -9.784 7.755 39.406 O3' -4.254 6.411 41.169 9 C P -3.624 7.180 42.396 O3' -0.512 7.786 37.956 10 G P 0.558 7.368 36.842 O3' 1.277 2.396 35.477 11 G P 2.269 2.799 34.333 O3' 2.889 1.221 29.485 12 U P 4.213 2.020 29.149 O3' 5.337 3.251 24.490 13 C P 6.623 4.128 24.805 O3' 8.244 7.781 21.718 14 G P 9.631 8.457 22.177 O3' 11.197 13.207 23.358 15 G P 12.504 12.771 24.171 O3' 14.528 15.560 27.404 16 A P 15.984 14.907 27.533 O3' 18.510 15.652 31.986 17 U P 19.906 14.896 32.054 O3' 22.301 12.197 35.502 18 C P 23.376 11.437 34.604 O3' 25.181 6.885 37.016 9 10 ! ! ! SG1 1 1 SG2 6 10 SG3 14 14 1 0.000 475.424 2 7.728 487.854 3 20.609 508.569 4 33.489 529.285 5 46.370 550.000 6 438.538 429.324 7 438.538 414.688 8 438.538 400.052 9 438.538 385.416 10 438.538 370.780 11 438.538 356.144 12 438.538 331.750 13 438.538 307.357 14 438.538 136.603 15 438.538 87.816 16 438.538 63.423 17 438.538 39.029 18 438.538 14.636 2 18 + + c 3 17 - - c 4 16 - - c 5 15 + + c 7 14 + + c 12 9 W S t 13 13 + + c 14 12 - - c 15 11 + + c 17 8 W H t 18 10 + + c 19 5 - - c 20 4 + + c 21 3 W W c 22 2 + + c 6 13 ! ! ! 19 10 ! ! ! 2 18 4 13 13 3 19 5 4