The recA gene from Streptomyces rimosus R6: sequence and expression in Escherichia coli

Abstract

The recA gene from Streptomyces rimusus encodes a 376-amino acids polypeptide (M(r) 39,702) that is one of the largest bacterial RecA proteins observed. Detailed analyses of the Streptomyces RecA proteins showed that all possess an additional and unique C-terminal, rich in lysines and alanines, which can form an additional terminal alpha helix. Expression of the S. rimosus RecA protein in Escherichia coli FR333 (delta recA306) was demonstrated using antibodies raised against E. coli RecA protein; expression was possible only from the S. rimosus promoter. A Streptomyces-E. coli-like promoter sequence (TTGACA-18bp-TCTTAT) was found in the A+ T-rich region 135-165 base pairs upstream from the initiation codon and was related to Bacillus subtilis DNA damage-inducible promoters.