biostudies-literatureFalchi FAUniversità degli Studi di Napoli Federico IIUniversità degli Studì di MilanoE826https://www.ebi.ac.uk/biostudies/studies/S-EPMC7356881biostudies-literatureUnknown8(6)LpxT is an inner membrane protein that transfers a phosphate group from the essential lipid undecaprenyl pyrophosphate (C-55PP) to the lipid A moiety of lipopolysaccharide, generating a lipid A <i>tris</i>-phosphorylated species. The protein is encoded by the non-essential <i>lpxT</i> gene, which is conserved in distantly related Gram-negative bacteria. In this work, we investigated the phenotypic effect of <i>lpxT</i> ectopic expression from a plasmid in <i>Escherichia coli</i>. We found that <i>lpxT</i> induction inhibited cell division and led to the formation of elongated cells, mostly with absent or altered septa. Moreover, the cells became sensitive to detergents and to hypo-osmotic shock, indicating that they had cell envelope defects. These effects were not due to lipid A hyperphosMicroorganismsOverexpression of <i>lpxT</i> Gene in <i>Escherichia coli</i> Inhibits Cell Division and Causes Envelope Defects without Changing the Overall Phosphorylation Level of Lipid A.PMC7356881E66C18001330003naMolinaro ABriani FParoni MFalchi FADi Lorenzo FPizzoccheri RForti FCasino GfalseOverexpression of <i>lpxT</i> Gene in <i>Escherichia coli</i> Inhibits Cell Division and Causes Envelope Defects without Changing the Overall Phosphorylation Level of Lipid A.LpxT is an inner membrane protein that transfers a phosphate group from the essential lipid undecaprenyl pyrophosphate (C-55PP) to the lipid A moiety of lipopolysaccharide, generating a lipid A <i>tris</i>-phosphorylated species. The protein is encoded by the non-essential <i>lpxT</i> gene, which is conserved in distantly related Gram-negative bacteria. In this work, we investigated the phenotypic effect of <i>lpxT</i> ectopic expression from a plasmid in <i>Escherichia coli</i>. We found that <i>lpxT</i> induction inhibited cell division and led to the formation of elongated cells, mostly with absent or altered septa. Moreover, the cells became sensitive to detergents and to hypo-osmotic shock, indicating that they had cell envelope defects. These effects were not due to lipid A hyperphos2020-01-01T00:00:00Z2020 May2026-04-29T08:43:46.4Z2026-04-14T03:06:45.763ZS-EPMC73568813248632910.3390/microorganisms8060826