ArcA regulator of gamma-proteobacteria: Identification of the binding signal and description of the regulon

Basing on a common signal previously identified in nine regions upstream of Escherichia coli genes regulated by ArcA, orthologous ArcA-regulated genes were identified in genomes of gamma-proteobacteria: Escherichia coli, Yersinia pestis, Pasteurella multocida, and Vibrio vulnificus. In addition to 10 genes in the training set, 23 new genes with conserved candidate ArcA-binding sites were identified. Fourteen of them have been described in the literature as transcriptionally regulated depending on the oxygen level. A candidate site upstream of arcA makes it plausible that this gene is autoregulated by the negative feedback loop mechanism.