Cloning and characterization of a cluster of linked Bacillus subtilis late competence mutations

摘要: We characterized a segment of chromosomal DNA from Bacillus subtilis that was required for the development genetic competence. The cloned group genetically linked and phenotypically similar Tn917lac insertion mutants deficient in This cluster mutations defined comG locus. Chromosomal flanking each six insertions cloned. Restriction maps plasmids revealed their inserts consisted overlapping fragments. These data, together with Southern blots mutants, showed occurred following order: comG12, comG39, comG412, comG107, comG56, comG210. Expression promoter located upstream first insertion, comG12. determined by low-resolution S1 nuclease mapping 3' terminus. region spanned about 5 kilobase pairs, based on transcription terminator Northern blotting. comG12 mutation had partial epistatic effect expression one other com locus, comE, but none affected this or any gene tested. Based these conclusions, its size phenotype, locus must be organized as polycistronic operon is subject to competence-specific regulation.