Cloning, sequencing, and transcriptional analysis of the recA gene of Pseudomonas cepacia

Abstract

A recombinant plasmid carrying the recA gene of Pseudomonas cepacia complements a recA mutation of Escherichia coli and restores UV and methylmethane sulfonate resistance, as well as recombinational proficiency. The predicted amino acid (aa) sequence of P. cepacia RecA (347 aa; Mr, 37256) is highly homologous to the RecA proteins from Thiobacillus ferrooxidans (74% aa homology), Pseudomonas aeruginosa (72%), E. coli (71%), Anabaena variabilis (61%), and Synechococcus sp. strains PCC7002 (59%). The transcription of the recA gene in P. cepacia and E. coli, which starts at almost the same site, was enhanced slightly by UV irradiation in the former and markedly in the latter bacteria. An SOS box characteristic to LexA-regulated promoters, along with the -10 and -35 consensus sequences, was found in the 5' upstream region of the P. cepacia recA gene.