title: Mutation of serine residue 318 in the class C beta-lactamase of Enterobacter cloacae 908R.
abstract: The involvement of the serine residue 318 in the specificity of a class C beta-lactamase was investigated. Multiple site-directed mutants at this position were generated using a polymerase chain reaction technique. These mutants were then probed for their activity towards various beta-lactam compounds. One mutant, S318G was further purified and its physico-chemical and catalytic properties determined. It was shown that the observed minimal inhibitory concentration values of this mutant could be correlated to its kinetic properties using a 'diffusion-hydrolysis' model. However, the data showed that residue 318 has little influence on the specificity of class C beta-lactamases.
authors.affiliation: Centre d'Ingénierie de Protéines, Université de Liège, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Jacobs
authors.forename: A
authors.initials: A
authors.lastname: Dubus
authors.forename: D
authors.initials: D
authors.lastname: Monnaie
authors.forename: S
authors.initials: S
authors.lastname: Normark
authors.forename: J M
authors.initials: JM
authors.lastname: Frère
mesh_terms: D001483:Base Sequence; D004352:Drug Resistance, Microbial / Q000235:genetics*; D016972:Enterobacter cloacae / Q000201:enzymology*; D007700:Kinetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011489:Protein Denaturation; D013379:Substrate Specificity; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D001618:beta-Lactamases