Figure 2.

The three categories of co-evolutionary pattern between S7 and S13 cooperative pair are shown. The proteins and 16S rRNA are presented as cartoon views. Each dotted line represents co-evolution between two residues it connects. Green lines represent direct co-evolution (e.g. 54Ser of S7 co-evolves with 48Leu of S13), blue lines represent indirect co-evolution (e.g. 103Trp of S7 and 1Met of S13 co-evolve with 947G of 16S rRNA) and red lines signify third-party co-evolution (1336C co-evolves with 950U). Only some residue positions are highlighted to maintain the clarity of the image.