title: Role of the Ser-287-Asn replacement in the hydrolysis spectrum extension of AmpC beta-lactamases in Escherichia coli.
abstract: Two AmpC variants harboring the S287N substitution were obtained by mutagenesis from cephalosporinases representative of the phylogenetic groups A and B2 of Escherichia coli. Their biochemical characterization revealed that the S287N replacement led to an important increase in the catalytic efficiency toward extended-spectrum cephalosporins in the AmpC beta-lactamase of group A only.
authors.affiliation: Service de Bactériologie-Hygiène, Centre Hospitalier Universitaire d'Amiens, Hôpital Nord, Amiens, France. hedi.mammeri@bct.aphp.fr
authors.forename: Hedi
authors.initials: H
authors.lastname: Mammeri
authors.forename: Moreno
authors.initials: M
authors.lastname: Galleni
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D001216:Asparagine / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002511:Cephalosporins / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D017433:Protein Structure, Secondary; D012694:Serine / Q000235:genetics / Q000502:physiology*; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D002511:Cephalosporins; D029968:Escherichia coli Proteins; D012694:Serine; D001216:Asparagine; C048795:AmpC beta-lactamases; D001618:beta-Lactamases