RRC ID 35646
Author Mahalakshmi S, Sunayana MR, SaiSree L, Reddy M.
Title yciM is an essential gene required for regulation of lipopolysaccharide synthesis in Escherichia coli.
Journal Mol Microbiol
Abstract The outer membrane of Gram-negative bacteria is an asymmetric lipid bilayer consisting of an essential glycolipid lipopolysaccharide (LPS) in its outer leaflet and phospholipids in the inner leaflet. Here, we show that yciM, a gene encoding a tetratricopeptide repeat protein of unknown function, modulates LPS levels by negatively regulating the biosynthesis of lipid A, an essential constituent of LPS. Inactivation of yciM resulted in high LPS levels and cell death in Escherichia coli; recessive mutations in lpxA, lpxC or lpxD that lower the synthesis of lipid A, or a gain of function mutation in fabZ that increases the formation of membrane phospholipids, alleviated the yciM mutant phenotypes. A modest increase in YciM led to significant reduction of LPS and increased sensitivity to hydrophobic antibiotics. YciM was shown to regulate LPS by altering LpxC, an enzyme that catalyses the first committed step of lipid A biosynthesis. Regulation of LpxC by YciM was contingent on the presence of FtsH, an essential membrane-anchored protease known to degrade LpxC, suggesting that FtsH and YciM act in concert to regulate synthesis of lipid A. In summary, this study demonstrates an essential role for YciM in regulation of LPS biosynthesis in E. coli.
Volume 91(1)
Pages 145-57
Published 2014-1-1
DOI 10.1111/mmi.12452
PMID 24266962
MeSH ATP-Dependent Proteases / genetics ATP-Dependent Proteases / metabolism Acyltransferases / genetics Acyltransferases / metabolism Amidohydrolases / genetics Amidohydrolases / metabolism Anti-Bacterial Agents / pharmacology Escherichia coli / drug effects Escherichia coli / enzymology* Escherichia coli / genetics Escherichia coli Proteins / genetics* Escherichia coli Proteins / metabolism* Gene Expression Regulation, Bacterial Genes, Bacterial* Genes, Essential Lipid A / biosynthesis* Membrane Proteins / genetics* Membrane Proteins / metabolism* Mutation Phenotype
IF 3.418
Times Cited 27
Prokaryotes E. coli ME9062(BW25113) JW1272-KC JW0175(ASKA-fabZ)(Keio)