FIGURE 5.

The three-way junctions belonging to family A. Ten three-way rRNAs junctions belong to family A. The name of the junction depends on the RNA to which it belongs and on the numbering of the three helices that are anchored to the junction. For a typical junction, the three-dimensional stereo view (DeLano Scientific, http://www.pymol.org) is shown on the right and the secondary structure with secondary and tertiary interactions is represented on the left (Yang et al. 2003). For the other junctions, only the secondary structure diagrams with the symbols for the tertiary contacts are shown. The symbols used are according to the Leontis and Westhof (2001) nomenclature.