Physical mapping of Bacillus subtilis phage rho14 cloning vehicles: heteroduplex and restriction enzyme analyses

Four deletion mutants of temperate Bacillus subtilis bacteriophage rho14 have been examined utilizing restriction enzyme and DNA heteroduplex methods. This has allowed the orientation and mapping of the deletions on the rho14 physical map. A continuous 15% of the genome contains functions not essential for bacteriophage viability. A 7% subsection of this region contains phage immunity functions. The deletions were found to range in size from about 2.2-3.3 kilobases. In addition, the deletion mutants retain a single Sal I restriction site, which is currently being used as a cloning site for recombinant DNA. We have located the Sal I site to be 400 basepairs from the immunity region. Thus, the clear- and turbid-plaque deletion mutants are all capable of being utilized as molecular cloning vehicles for Bacillus subtilis.