Figure 5.

Comparison between distribution of the second position amino acid in all yeast proteins and conserved yeast proteins that have orthologs in human. The prevalence of the second amino acid in a subset of yeast (S. cerevisiae) proteins that have human orthologs (“conserved”, n=218) was compared with the prevalence in the total number of yeast proteins examined (“all”, n=4,819). The figure indicates a significant increase in the fraction of proteins containing Ser at the second position in the subset of “conserved” yeast proteins. An increase is also apparent for Ala and Gly, but to a lesser extent.