The isolation of lambda phage carrying DNA from the histidine and isoleucine-valine regions of the Bacillus subtilis chromosome

Abstract

From a lambda gtWES library of the chromosome of Bacillus subtilis, phages carrying DNA from the hisA and ilv-leu regions were isolated. They were identified by their ability to form complementing plaques on hisB, ilvC or leuB mutants of Escherichia coli K12 under selective conditions and in the presence of a helper phage. The his phages complemented E. coli his A, B or D mutations and could transform seven mutations in the hisA region of the B. subtilis chromosome; each carried a single EcoR1 insert of about 8.2 kb. Phages complementing E. coli ilvC or leuB mutations and carrying the equivalent B. subtilis genes ilvC and leuC transformed a range of mutations in the B. subtilis ilv-leu region. The distribution of genetic markers carried by the phages suggests that the entire ilv-leu cluster from az1A through leuD is covered in the collection of phages obtained and is carried in three EcoR1 restriction fragments of approximately 6.7, 4.7 and 2.85 kb.