Characterization of the recA gene of Vibrio anguillarum

We have cloned and sequenced the recA gene from two strains, 775 and 531A, of the fish pathogen, Vibrio anguillarum. Although both strains showed different sensitivities to methyl methanesulfonate (MMS), the recA genes were identical. In vitro expression of the V. anguillarum recA gene produced a polypeptide of about 40 kDa, in agreement with the value obtained from the nucleotide sequence. We identified the transcription start point by primer extension. The promoter for the recA gene mapped to an SOS regulatory element. The presence of an SOS box suggests that a LexA-like mediated response system may exist in V. anguillarum. The deduced RecA amino acid sequence is highly homologous with Escherichia coli RecA and other RecA proteins. Domains important in RecA function are conserved. We provide a comparative analysis of the activities and features of RecA analogs from a variety of species. We observed that certain residues that could be important in protein conformation are conserved in RecA proteins across a diverse range of bacterial species.