title: Identification of a UDP-Gal: GlcNAc-R galactosyltransferase activity in Escherichia coli VW187.
abstract: A novel acceptor substrate for galactosyltransferase was synthesized containing GlcNAcalpha-pyrophosphate, covalently bound to a hydrophobic phenoxyundecyl moiety (GlcNAc alpha-O-PO(3)-PO(3)-(CH(2))(11)-O-Phenyl). The new substrate was used to develop an assay for a galactosyltransferase activity from Escherichia coli strain VW187 that is involved in lipopolysaccharide synthesis and has not been studied by others. We showed that Gal was transferred from UDP-Gal to the novel acceptor substrate. This was a significant improvement over our previous preliminary assays of the enzyme using endogenous substrate, and showed that these synthetic substrates are useful for assaying enzymes that utilize lipid-bound substrates in O-chain synthesis in Gram-negative bacteria.
authors.affiliation: Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Montoya-Peleaz
authors.forename: John G
authors.initials: JG
authors.lastname: Riley
authors.forename: Walter A
authors.initials: WA
authors.lastname: Szarek
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valvano
authors.forename: John S
authors.initials: JS
authors.lastname: Schutzbach
authors.forename: Inka
authors.initials: I
authors.lastname: Brockhausen
mesh_terms: D029968:Escherichia coli Proteins / Q000302:isolation & purification* / Q000378:metabolism; D005700:Galactosyltransferases / Q000378:metabolism*; D005964:Glucosyltransferases; D006801:Humans; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014531:Uridine Diphosphate Galactose / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D014531:Uridine Diphosphate Galactose; D005700:Galactosyltransferases; D005964:Glucosyltransferases; C059055:N-acetylglucosaminyldiphosphoundecaprenol glucosyltransferase