The Role of the envM Genes of Escherichia coli and Salmonella typhimurium in Cell Membrane Biosynthesis

Abstract

Inhibition of the envM gene product by incubation of the conditional envM mutant Escherichia coli JP1111 at the nonpermissive temperature or by diazaborine treatment leads to pleiotropic effects on cell membrane composition. One of the most pronounced effects is the inhibition of phospholipid biosynthesis. The changes in the membrane structure lead to cell death without apparent lysis of the cells. The characteristic morphological changes are the retraction of the cytoplasmic membrane which leaves empty zones mainly at the poles of the cells. Overproduction of the wild type EnvM protein in the envM mutant at the nonpermissive temperature initially complements the ts phenotype but finally causes cell lysis.