Genes Preferring Non-AUG Start Codons in Bacteria

Abstract

Here we investigate translational regulation in bacteria by analyzing the distribution of start codons in fully assembled genomes. We report 36 genes (infC, rpoC, rnpA, etc.) showing a preference for non-AUG start codons in evolutionarily diverse phyla ("non-AUG genes"). Most of the non-AUG genes are functionally associated with translation, transcription or replication. In E. coli, the percentage of essential genes among these 36 is significantly higher than among all genes. Furthermore, the functional distribution of these genes suggests that non-AUG start codons may be used to reduce gene expression during starvation conditions, possibly through translational autoregulation or IF3-mediated regulation.