Influence of domain architecture and codon usage pattern on the evolution of virulence factors of Vibrio cholerae

Cholera remains a heavy burden to human health in some developing countries including India where sanitation is poor and health care is limited. After the publication of the complete genome sequence of Vibrio cholerae, the etiological agent of cholera, extensive possibilities, earlier unavailable, have opened up to understand the genetic organization of V. cholerae. In the present study, we analyzed all the pathogenic non-horizontally transferred genes of V. cholerae to know the ancestral relationship and how the pathogenic genes have been evolved in V. cholerae genome. We observed that protein domain has important role in developing pathogenicity, and codon usage pattern of the pathogenic protein domain is also subject to selection. The present study unambiguously depict that the patterns of synonymous codon usage within a protein domain can change dramatically during the course of evolution to give rise to pathogenicity.