Insertion of bacteriophage SP beta into the citF gene of Bacillus subtilis and specialized transduction of the ilvBC-leu genes.

We isolated a strain of Bacillus subtilis in which the SP beta c2 prophage is inserted into the citF (succinate dehydrogenase) gene. Defective specialized transducing particles for the ilvBC-leu genes were isolated from phage-induced lysates of this lysogen. We isolated a group of phages that differ in the amount of genetic material they carry from this region. Also, we incorporated mutant ilv and leu alleles into the genomes of several transducing phages. Our phage collection enables us to identify the cistron of new ilv and leu mutations by complementation analysis. In this process we discovered a fourth leu cistron, leuD. Characterization of the phages confirmed the published gene order: ilvB-ilvC-leuA-leuC-leuB; leuD lies to the right of leuB.