title: Biosynthesis of osmoregulated periplasmic glucans in Escherichia coli: the membrane-bound and the soluble periplasmic phosphoglycerol transferases are encoded by the same gene.
abstract: In Escherichia coli, osmoregulated periplasmic glucans (OPGs) are highly substituted by phosphoglycerol, phosphoethanolamine and succinyl residues. A two-step model was proposed to account for phosphoglycerol substitution: first, the membrane-bound phosphoglycerol transferase I transfers residues from membrane phosphatidylglycerol to nascent OPG molecules; second, the periplasmic phosphoglycerol transferase II swaps residues from one OPG molecule to another. Gene opgB was reported to encode phosphoglycerol transferase I. In this study, we demonstrate that the periplasmic enzyme II is a soluble form of the membrane-bound enzyme I. In addition, timing of OPG substitution was investigated. OPG substitution by succinyl residues occurs rapidly, probably during the backbone polymerization, whereas phosphoglycerol addition is a very progressive process. Thus, both phosphoglycerol transferase activities appear biologically necessary for complete OPG substitution.
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL/CNRS 8576 IFR147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, Cedex, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Lequette
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL/CNRS 8576 IFR147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, Cedex, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Lanfroy
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL/CNRS 8576 IFR147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, Cedex, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Cogez
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL/CNRS 8576 IFR147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, Cedex, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bohin
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL/CNRS 8576 IFR147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, Cedex, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Lacroix
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D050939:Gene Fusion; D005798:Genes, Bacterial; D005936:Glucans / Q000378:metabolism*; D020404:Glycerophospholipids / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D033903:Periplasmic Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000032:analysis; D017422:Sequence Analysis, DNA; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D014169:Transformation, Bacterial; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
chemical_list: D005936:Glucans; D020404:Glycerophospholipids; D008565:Membrane Proteins; D033903:Periplasmic Proteins; D011993:Recombinant Fusion Proteins; D017855:Transferases (Other Substituted Phosphate Groups); C037247:phosphatidylglycerol - membrane-oligosaccharide glycerophosphotransferase; D001618:beta-Lactamases