CLONING, CHARACTERIZATION AND EXPRESSION OF THE RECA GENE OF AEROMONAS-SALMONICIDA

The Aeromonas salmonicida A449 recA gene has been cloned, sequenced an d expressed in vitro. The predicted amino acid sequence of A. salmonic ida RecA was determined and, when compared to other RecA, was found to possess a number of domains identical to those characterized in Esche richia coli RecA. The A. salmonicida recA was mobilized into an E. col i recA mutant strain and was shown to allow increased survival in the presence of the chemical mutagen MMS and after ultraviolet (UV) irradi ation. The A. salmonicida recA also possesses a potential regulatory S OS box in the DNA 5' of the gene. The rate of A. salmonicida-mediated recombination in E. coli was increased by exposure to UV light, which suggests that SOS induction in A. salmonicida parallels that of E. col i.