The Azotobacter vinelandii recA gene: sequence analysis and regulation of expression

Abstract

The nucleotide (nt) sequence of the Azotobacter vinelandii recA gene (Av-recA) was determined and compared with the recA sequences from Pseudomonas aeruginosa (Pa-recA), a soil bacterium, and Escherichia coli (Ec-recA), an enteric bacterium. The Av-recA gene and the deduced aa sequence were found to be more similar to their Pa-recA counterparts than to the Ec-recA gene and protein. Expression of Av-recA was found to be autoregulatory. Unlike Ec-recA and Pa-recA, however, expression of Av-recA was weakly enhanced upon DNA damage. In E. coli, expression of an Av-recA::lacZ fusion was poor, but its autoregulation was similar to that of Ec-recA. Av-recA expression, however, could not induce the repair system response in E. coli.