Characterization of a novel lipoprotein mutant in Escherichia coli.

Mutants altered in the structural gene for murein lipoprotein in Escherichia coli can be isolated by globomycin selection. We have isolated a unique globomycin-resistant mutant, strain 6-23, which synthesizes a structurally altered, albeit modified and processed, lipoprotein. DNA sequence analysis of the mutant lpp allele and determination of the amino acid composition of the mutant lipoprotein revealed a single amino acid substitution of cysteine for arginine at the 68th amino acid residue of prolipoprotein. Pulse-chase experiments revealed that the kinetics of lipoprotein maturation was affected by this alteration in the structure of lipoprotein.