Cloning of DNA fragments of the right end of phage Mu and location of the HindIII, SalI, PstI, and BamHI restriction sites on the genetic map of Mu

Abstract

The construction of three new plasmids containing the right, variable end of phage Mu DNA is described. They complete a collection of pKN plasmids derived by cloning specific restriction fragments of Mu DNA into plasmid cloning vehicles. The collection contains different length Mu DNA segments which encompass the entire phage genome. The Mu-specific genetic information of each cloned fragment was determined by marker rescue analysis of plasmid-containing strains with Mu amber mutant phages characterized by O'Day et al. (K. O'Day, D. W. Schultz, W. Ericsen, L. Rawluk, and M. M. Howe, 1979, Virology 93, 320–328). This analysis demonstrated the location of the HindIII, SalI, PstI, and BamHI restriction sites on the genetic map of Mu and located the new essential genes V, W, and Y on specific restriction fragments of the physical map of Mu DNA. This plasmid bank has thus allowed a further refinement in the correlation of the genetic and physical maps of Mu DNA and should provide a useful source of specific DNA segments for further genetic and biochemical analysis of Mu functions.