Amino acid cluster diagram. The amino acid frequencies based cluster diagram is made from the amino acid usage found in the predicted genes of the genomes in question. Amino acid frequencies correlate strongly with codon usage frequencies, but at a lower resolution. It can be seen that only small differences can be detected between species in genus Brucella.
Bohlin et al. BMC Evolutionary Biology 2010 10:249 doi:10.1186/1471-2148-10-249