Figure 3.

Part of 3D structural alignment of E. coli and H. marismortui 23S rRNAs, illustrating structural conservation of a complex motif of Domain I that includes Helix 24. (a) The 3D structural alignment ofcorresponding base pairs from the E. coli (left) and H. marismortui (right) structures. (b) The annotated 2D structures for E. coli and H. marismortui using the base pair symbols. (c) Stereo view of the E. coli 3D structure, highlighting bases that differ between structures. The base pairs in the alignment and in the 2D and 3D structures are color-coded by geometric base pair family. Letters that correspond to bases which differ between organisms are marked in the secondary structure by a magenta circle and in the 3D structure with thicker lines.