Figure 4
Functional divergence-related amino acid site candidates (posterior probability, Q k > 0.7). A site-specific profile based on the posterior probability (Qk )was used to identify the critical amino acid sites responsible for the functional divergence between the non-TIR- and TIR-NBS RGA subfamilies. According to the definition, a large Qk value indicates a high possibility that the functional constraint of a site is different between the two subfamilies. A) non-TIR-NBS subfamily, B) TIR-NBS subfamily and C) Qk values of 13 amino acid sites. The threshold (%) for shading was set at 50. Similar amino acid residues are shaded grey, and identical amino acid residues are shaded black.