Functional distribution of orthologs divided by low or high nonsynonymous substitution rate (dN). The graph was generated using 985 orthologs with dS < 5; they were divided as described in the Methods section. Functions were grouped into Metabolism (1, amino acid biosynthesis; 2, nucleotide biosynthesis; 3, fatty acid biosynthesis; 4, cofactor biosynthesis; 5, central intermediary metabolism; and 6, energy generation), Information (7, DNA metabolism; 8, transcription; 9, translation; and 10, transcriptional regulators), Processes (11, transport; 12, cellular envelope synthesis; and 13, other cellular processes), and 14, Hypothetical functions. Bar colors: red, orthologs with low dN; blue, orthologs with high dN. Asterisks denote significant differences with p < 0.05, Fisher's exact test.