Figure 10.
Calculated model of the internal loop of the 39 nt hairpin construct. (a) G10 stacked in the helix with a syn conformation. (b) G10 flipped out of the helix with an anti conformation. G10 was also observed in syn and anti conformations flipped out of and stacked in the helix, respectively. The averages of G10 chemical shifts calculated with NUCHEMICS47 for the 20 structures with the lowest distance restraint violation energies generated by simulated annealing are consistent with the structural ensemble. (c) Space-filling model of the G11-A31 pair.