1 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 GGCACGAGGU UUAGCUACAC UCGUGCC LOOP1 12 15 Crystallography ? ? Angstroms 1 G O3' 11.464 -17.110 2.124 2 G P 10.940 -16.357 3.460 O3' 13.586 -12.385 5.866 3 C P 12.646 -11.589 6.916 O3' 13.168 -6.776 8.442 4 A P 11.717 -6.231 8.877 O3' 10.580 -1.329 8.843 5 C P 8.982 -1.146 8.917 O3' 6.770 3.259 6.665 6 G P 5.173 3.116 6.437 O3' 3.095 5.244 1.724 7 A P 3.129 6.714 1.049 O3' 1.232 4.764 -3.600 8 G P 0.224 4.726 -4.864 O3' -0.392 1.755 -8.979 9 G P -1.593 2.710 -9.445 O3' -7.181 3.018 -9.248 10 U P -8.245 4.164 -8.865 O3' -13.722 3.270 -6.428 11 U P -14.957 3.614 -5.437 O3' -16.968 4.690 -1.944 12 U P -17.291 6.269 -1.928 O3' -17.482 9.338 2.105 13 A P -17.772 10.335 0.867 O3' -12.233 13.003 0.068 14 G P -10.653 12.624 -0.066 O3' -8.472 10.792 2.196 15 C P -7.061 11.532 1.850 O3' -6.785 9.038 6.597 16 U P -7.174 9.688 8.030 O3' -9.658 4.511 9.189 17 A P -9.262 2.946 9.075 O3' -13.822 -0.188 6.216 18 C P -14.493 -1.413 5.402 O3' -12.680 -4.934 2.761 19 A P -12.883 -6.101 3.857 O3' -9.295 -8.673 0.915 20 C P -10.692 -9.375 0.464 O3' -6.611 -9.726 -2.645 21 U P -5.584 -10.767 -1.957 O3' -3.443 -7.090 -5.643 22 C P -2.933 -6.627 -7.102 O3' 2.160 -5.187 -8.236 23 G P 2.478 -3.838 -9.069 O3' 6.193 -0.641 -8.200 24 U P 7.717 -0.914 -8.647 O3' 11.909 1.640 -7.313 25 G P 13.159 0.646 -7.522 O3' 17.377 1.164 -4.456 26 C P 18.360 -0.086 -4.724 O3' 21.207 -2.238 -0.732 27 C P 22.150 -3.316 -1.471 O3' 22.592 -8.289 0.642 18 syn 1 27 + + c 2 26 + + c 3 25 + + c 4 24 - - c 5 23 + + c 6 22 + + c 7 21 - - c 8 20 + + c 9 18 + + c 10 17 - - c 11 16 W W c 12 14 ! ! ! 15 16 ! ! ! 1 27 8 9 18 3 SG1 12 15 SG2 19 19 1 107.289 0.000 2 107.289 42.319 3 107.289 84.638 4 107.289 126.957 5 107.289 169.276 6 107.289 211.595 7 107.289 253.914 8 107.289 296.233 9 107.289 380.871 10 107.289 423.190 11 107.289 465.509 12 113.011 513.710 13 80.776 550.000 14 32.236 550.000 15 0.000 513.710 16 5.723 465.509 17 5.723 423.190 18 5.723 380.871 19 5.723 338.552 20 5.723 296.233 21 5.723 253.914 22 5.723 211.595 23 5.723 169.276 24 5.723 126.957 25 5.723 84.638 26 5.723 42.319 27 5.723 0.000