CLONING AND SEQUENCE-ANALYSIS OF A RECA-LIKE GENE FROM STREPTOMYCES-VENEZUELAE ISP5230

When genomic DNA fragments from Streptomyces venezuelae ISP5230 were p robed at moderate stringency with recA from Mycobacterium tuberculosis , a 2.0-kb SmaI fragment was identified. The fragment was isolated by cloning a BamHI digest of S. venezuelae DNA in pHJL400 and screening t he plasmids in Escherichia coli by Southern hybridization using a sib- selection technique. Sequencing the hybridizing region located an open reading frame encoding 377 amino acids. Its deduced amino acid sequen ce resembled that of recA genes from other bacteria. The cloned S. ven ezuelae gene conferred partial resistance to ethylmethanesulfonate whe n expressed in E. coli from the lacZ promoter.