title: Expression and characterization of the isolated glycosyltransferase module of Escherichia coli PBP1b.
abstract: The enzymes involved in the biosynthesis of peptidoglycan are targets for the development of new antibiotics. The bifunctional high molecular weight (HMW) penicillin-binding proteins (PBPs), which contain both glycosyltransferase (GTase) and transpeptidase (TPase) activities, are particularly attractive targets because of their extracellular location. However, there is limited mechanistic or structural information about the GTase modules of these enzymes. In this paper, we describe the overexpression and characterization of the GTase module of Escherichia coli PBP1b, a paradigm of the HMW PBPs. We define the C-terminal boundary of the GTase module and show that the isolated module can be overexpressed at significantly higher levels than the full-length protein. The catalytic efficiency and other characteristics of the isolated module are comparable in most respects to the full-length enzyme. This work lays the groundwork for mechanistic and structural analysis of GTase modules.
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Dianah S
authors.initials: DS
authors.lastname: Barrett
authors.forename: Lan
authors.initials: L
authors.lastname: Chen
authors.forename: Nadia K
authors.initials: NK
authors.lastname: Litterman
authors.forename: Suzanne
authors.initials: S
authors.lastname: Walker
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis / Q000187:drug effects; D003902:Detergents / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins; D016695:Glycosyltransferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D006602:Hexosyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D015394:Molecular Structure; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D046915:Penicillin-Binding Proteins; D046928:Peptidoglycan Glycosyltransferase; D010458:Peptidyl Transferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017384:Sequence Deletion; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D003902:Detergents; D029968:Escherichia coli Proteins; D008670:Metals; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D016695:Glycosyltransferases; D006602:Hexosyltransferases; D046928:Peptidoglycan Glycosyltransferase; C478681:penicillin-binding protein 1B, E coli; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase; D002267:Muramoylpentapeptide Carboxypeptidase