Preferential selection of deletion mutations of the outer membrane lipoprotein gene of Escherichia coli by globomycin

Globomycin is an antibiotic which inhibits the processing of the prolipoprotein. Eighty globomycin-resistant mutants were independently isolated from E. coli K-12 which had a deletion mutation in chromosomal lipoprotein gene (lpp), but contained a plasmid carrying the wild-type lpp gene. Twenty-six of the mutants did not have the lipoprotein in the membrane fractions. From the analysis of the plasmids of these mutants, all of the lipoprotein-deficient mutations were found to be due to deletion mutations around the lpp gene.