1 21 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 GCGUCACACC GGUGAAGUCG C Crystallography ? ? Angstroms 1 G P -11.035 27.282 11.550 O3' -13.128 22.677 11.910 2 C P -12.115 21.541 11.395 O3' -13.367 17.372 9.132 3 G P -11.953 16.692 8.802 O3' -11.403 13.730 4.985 4 U P -9.906 13.174 4.858 O3' -6.365 12.806 0.494 5 C P -4.776 12.849 0.687 O3' -1.753 14.301 -3.190 6 A P -0.219 14.220 -2.698 O3' 3.390 17.305 -4.528 7 C P 4.639 16.473 -3.943 O3' 8.539 19.194 -2.003 8 A P 9.462 17.947 -1.591 O3' 12.646 18.436 2.494 9 C P 13.228 16.939 2.652 O3' 13.642 15.176 7.619 10 C P 14.008 13.634 7.945 O3' 13.265 11.081 12.199 11 G P 13.924 9.637 11.909 O3' 11.897 5.285 13.737 12 G P 12.556 4.026 12.985 O3' 9.744 -0.330 12.280 13 U P 10.803 -1.337 11.596 O3' 8.363 -4.745 8.239 14 G P 9.432 -5.684 7.483 O3' 8.845 -7.359 2.753 15 A P 10.138 -8.289 2.957 O3' 13.399 -8.585 -0.766 16 A P 14.161 -7.345 -1.466 O3' 18.068 -8.199 -5.161 17 G P 18.770 -6.823 -4.710 O3' 20.825 -3.755 -7.646 18 U P 22.322 -3.680 -7.068 O3' 25.512 0.245 -7.032 19 C P 26.950 -0.148 -6.423 O3' 30.251 2.444 -3.663 20 G P 31.476 1.477 -3.251 O3' 33.943 1.741 1.270 21 C P 34.923 0.483 1.459 O3' 35.683 -1.467 6.186 SG1 6 6 SG2 15 16 1 0.000 0.000 2 0.000 23.913 3 0.000 47.826 4 0.000 71.739 5 0.000 95.652 6 0.000 119.565 7 0.000 191.304 8 0.000 215.217 9 0.000 239.130 10 0.000 263.043 11 0.000 286.957 12 0.000 310.870 13 0.000 334.783 14 0.000 358.696 15 0.000 382.609 16 0.000 430.435 17 0.000 454.348 18 0.000 478.261 19 0.000 502.174 20 0.000 526.087 21 0.000 550.000 1 21 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 GCGUCACAC CGGUGAAGUC GC Crystallography ? ? Angstroms 1 G P 22.087 -11.734 7.365 O3' 23.191 -8.259 10.946 2 C P 22.346 -6.923 10.648 O3' 23.872 -2.327 12.015 3 G P 22.696 -1.322 11.588 O3' 23.444 3.581 9.989 4 U P 21.890 3.952 9.775 O3' 21.610 7.009 5.820 5 C P 20.277 7.629 5.155 O3' 18.788 8.623 -0.254 6 A P 17.202 8.876 -0.263 O3' 14.913 7.649 -4.660 7 C P 13.456 8.188 -4.242 O3' 9.429 5.401 -5.666 8 A P 8.188 6.159 -4.987 O3' 3.946 3.657 -3.618 9 C P 3.055 4.739 -2.836 O3' -0.077 2.735 0.878 10 C P -0.800 3.985 1.571 O3' -1.893 3.869 6.521 11 G P -2.466 5.330 6.866 O3' -1.978 7.390 11.356 12 G P -2.372 8.943 11.440 O3' 0.596 13.252 13.800 13 U P 0.212 14.790 13.626 O3' 3.313 18.608 14.521 14 G P 2.307 19.818 14.190 O3' 4.087 24.182 11.638 15 A P 2.789 24.841 12.320 O3' 1.188 28.220 8.273 16 A P 1.099 27.392 6.906 O3' -0.313 30.487 2.896 17 G P -0.630 29.028 2.264 O3' -1.835 28.867 -2.656 18 U P -3.436 29.021 -2.606 O3' -5.852 26.240 -6.185 19 C P -7.376 26.741 -6.090 O3' -11.215 23.626 -7.217 20 G P -12.550 24.468 -6.883 O3' -16.629 21.614 -5.251 21 C P -17.794 22.620 -4.780 O3' -21.129 21.685 -1.238 SG1 6 6 SG2 15 16 1 57.391 550.000 2 57.391 526.087 3 57.391 502.174 4 57.391 478.261 5 57.391 454.348 6 57.391 406.522 7 57.391 358.696 8 57.391 334.783 9 57.391 310.870 10 57.391 286.957 11 57.391 263.043 12 57.391 239.130 13 57.391 215.217 14 57.391 191.304 15 57.391 167.391 16 57.391 143.478 17 57.391 95.652 18 57.391 71.739 19 57.391 47.826 20 57.391 23.913 21 57.391 0.000 1 21 + + c 2 20 + + c 3 19 + + c 5 17 + + c 7 14 + + c 8 13 - - c 9 12 + + c 10 11 + + c 11 10 + + c 12 9 + + c 13 8 - - c 14 7 + + c 17 5 + + c 18 4 W W c 19 3 + + c 20 2 + + c 21 1 + + c 4 18 ! ! ! 1 21 5 7 14 8 17 5 5