RRC ID 35423
Author Klein G, Lindner B, Brade H, Raina S.
Title Molecular basis of lipopolysaccharide heterogeneity in Escherichia coli: envelope stress-responsive regulators control the incorporation of glycoforms with a third 3-deoxy-α-D-manno-oct-2-ulosonic acid and rhamnose.
Journal J Biol Chem
Abstract Mass spectrometric analyses of lipopolysaccharide (LPS) from isogenic Escherichia coli strains with nonpolar mutations in the waa locus or overexpression of their cognate genes revealed that waaZ and waaS are the structural genes required for the incorporation of the third 3-deoxy-α-D-manno-oct-2-ulosonic acid (Kdo) linked to Kdo disaccharide and rhamnose, respectively. The incorporation of rhamnose requires prior sequential incorporation of the Kdo trisaccharide. The minimal in vivo lipid A-anchored core structure Kdo(2)Hep(2)Hex(2)P(1) in the LPS from ΔwaaO (lacking α-1,3-glucosyltransferase) could incorporate Kdo(3)Rha, without the overexpression of the waaZ and waaS genes. Examination of LPS heterogeneity revealed overlapping control by RpoE σ factor, two-component systems (BasS/R and PhoB/R), and ppGpp. Deletion of RpoE-specific anti-σ factor rseA led to near-exclusive incorporation of glycoforms with the third Kdo linked to Kdo disaccharide. This was accompanied by concomitant incorporation of rhamnose, linked to either the terminal third Kdo or to the second Kdo, depending upon the presence or absence of phosphoethanolamine on the second Kdo with truncation of the outer core. This truncation in ΔrseA was ascribed to decreased levels of WaaR glycosyltransferase, which was restored to wild-type levels, including overall LPS composition, upon the introduction of rybB sRNA deletion. Thus, ΔwaaR contained LPS primarily with Kdo(3) without any requirement for lipid A modifications. Accumulation of a glycoform with Kdo(3) and 4-amino-4-deoxy-l-arabinose in lipid A in ΔrseA required ppGpp, being abolished in a Δ(ppGpp(0) rseA). Furthermore, Δ(waaZ lpxLMP) synthesizing tetraacylated lipid A exhibited synthetic lethality at 21-23°C pointing to the significance of the incorporation of the third Kdo.
Volume 286(50)
Pages 42787-807
Published 2011-12-16
DOI 10.1074/jbc.M111.291799
PII M111.291799
PMID 22021036
PMC PMC3234843
MeSH Blotting, Western Escherichia coli / genetics Escherichia coli / metabolism* Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism Glycosyltransferases / genetics Glycosyltransferases / metabolism Lipopolysaccharides / chemistry Lipopolysaccharides / metabolism* Mass Spectrometry Membrane Proteins / genetics Membrane Proteins / metabolism Mutation RNA, Small Untranslated / genetics Rhamnose / chemistry* Sigma Factor / genetics Sigma Factor / metabolism Transcription Factors / genetics Transcription Factors / metabolism
IF 4.238
Times Cited 25
Prokaryotes E. coli JW3599(ASKA)