Switches in Genomic GC Content Drive Shifts of Optimal Codons under Sustained Selection on Synonymous Sites.

ABSTRACT: The major codon preference model suggests that codons read by tRNAs in high concentrations are preferentially utilized in highly expressed genes. However, the identity of the optimal codons differs between species although the forces driving such changes are poorly understood. We suggest that these questions can be tackled by placing codon usage studies in a phylogenetic framework and that bacterial genomes with extreme nucleotide composition biases provide informative model systems. Switches in the background substitution biases from GC to AT have occurred in Gardnerella vaginalis (GC = 32%), and from AT to GC in Lactobacillus delbrueckii (GC = 62%) and Lactobacillus fermentum (GC = 63%). We show that despite the large effects on codon usage patterns by these switches, all three species e

SUBMITTER: Sun Y 

PROVIDER: S-EPMC5629928 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature