Some viral bacteria exhibit codon bias

PHILADELPHIA, March 18 (UPI) -- U.S. biologists studying the genomes of viruses infecting the bacteria E. coli, P. aeruginosa and L. lactis found many of them exhibit codon bias.

The researchers at the University of Pennsylvania and Harvard University said codon bias is the tendency to preferentially encode a protein with a particular spelling. They analyzed patterns of codon usage across 74 bacteriophages and their findings extend the translational theory of codon bias to the viral kingdom, demonstrating the viral genome is selected to obey the preferences of its host.

"The host bacterium is exerting a strong evolutionary pressure on the virus," said Joshua Plotkin, lead author and an assistant professor at Penn. "This happens because a virus must hijack the machinery of its host in order to reproduce. We are seeing that viruses are forced to adopt the particular codon choices preferred by the bacterium they infect.

"Like a bee and a flower, an example of co-evolution between two large organisms, the same fundamental biological processes operate between two small organisms, as reflected in their genome sequences," Plotkin added.

The study that included Grzegorz Kudla at Penn and Julius Lucks and David Nelson at Harvard appeared in the journal PLoS Computational Biology.