Hallie Rane

5 August 2009

A Preliminary Search for Functional Divergence in Cytochrome c Family Proteins

Abstract

Whole genome sequencing has revealed a surprising abundance of multiheme cytochrome c proteins in bacteria; however, the cellular function of these proteins remains largely uncharacterized. Of particular interest is the organism Geobacter sulfurreducens, which is capable of metabolizing a number of metallic compounds and whose genome encodes an unusually high number of unique multiheme cyts c. We used a phylogenetic approach to investigate the evolution of cyt c proteins in G. sulfurreducens and other bacteria. Evidence of positive selection and functional divergence was found along many lineages, which may indicate that recent duplication and divergence of cyt c proteins has played a role in the emergence of novel metabolic strategies.