Codon usage in the Mycobacterium tuberculosis complex.
The usage of alternative synonymous codons in Mycobacterium tuberculosis (and M. bovis) genes has been investigated. This species is a member of the high-G+C Gram-positive bacteria, with a genomic G+C content around 65 mol%. This G+C-richness is reflected in a strong bias towards C- and G-ending codons for every amino acid: overall, the G+C content at the third positions of codons is 83%. However, there is significant variation in codon usage patterns among genes, which appears to be associated with gene expression level. From the variation among genes, putative optimal codons were identified for 15 amino acids. The degree of bias towards optimal codons in an M. tuberculosis gene is correlated with that in homologues from Escherichia coli and Bacillus subtilis. The set of selectively favoured codons seems to be quite highly conserved between M. tuberculosis and another high-G+C Gram-positive bacterium, Corynebacterium glutamicum, even though the genome and overall codon usage of the latter are much less G+C-rich.
Andersson
Siv G E
SGE
Department of Molecular Biology, Biomedical Center, Uppsala University, Uppsala, S-75124, Sweden.
Sharp
Paul M
PM
Department of Genetics, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
D001412:Bacillus subtilis / Q000235:genetics; D001482:Base Composition; D001483:Base Sequence; D003062:Codon / Q000235:genetics*; D003352:Corynebacterium / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D019143:Evolution, Molecular; D015870:Gene Expression; D005798:Genes, Bacterial; D009163:Mycobacterium bovis / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D013045:Species Specificity
D003062:Codon; D004269:DNA, Bacterial