Genetic characterization of a gene for prolipoprotein signal peptidase in Escherichia coli.

A mutation (lspA, prolipoprotein signal peptidase) rendering the prolipoprotein signal peptidase temperature-sensitive in Escherichia coli has been analyzed. The mutation was mapped in the dnaJ-rpsT-ileS-dapB region by interrupted mating with various Hfr strains and P1 phage transduction. lambda transducing phage lambda ddapB2 that carries the rpsT-ileS-dapB region was shown to complement the lspA mutation. Plasmid pLC3-13 which had been isolated from Clarke and Carbon's collection as a plasmid carrying the lspA locus was shown to carry the dnaJ and rpsT loci. Complementation analysis with plasmids carrying various DNA fragments derived from pLC3-13 showed that the lspA locus is between the rpsT and ileS loci. The wildtype allele was dominant over the lspA allele.