Figure 6. Arginine codon use plotted against the genomic GC content of the representative bacteria among the following groups.
A) Alphaproteobacteria; B) Betaproteobacteria; C) Gammaproteobacteria; D) Deltaproteobacteria; E) Actinobacteria; F) Bacteriodetes/Chlorobi; G) Cyanobacteria; H) Firmicutes. Arg-A and Arg-C refer to arginine codon families with either an A or a C in the first codon position, respectively.