Figure 6.

Comparison between distribution of the second position amino acid in human proteins translated from genes that have PPGs. Since PPGs are more commonly derived from highly expressed and evolutionary conserved genes, the prevalence of the second amino acid in a randomly picked subset of human proteins that have a PPG (“PPGs”, n=500) from www.pseudogene.org was compared with the prevalence in the total number of human proteins examined (“SwissProt”, n=10,790). The figure indicates a significant increase in the fraction of proteins containing Ala at the second position in the subset of “PPGs” human proteins. An increase is also apparent for Ser and Pro, but to a lesser extent.