title: Structure-function relationships of UMP kinases from pyrH mutants of Gram-negative bacteria.
abstract: Bacterial uridine monophosphate (UMP) kinases are essential enzymes encoded by pyrH genes, and conditional-lethal or other pyrH mutants were analysed with respect to structure-function relationships. A set of thermosensitive pyrH mutants from Escherichia coli was generated and studied, along with already described pyrH mutants from Salmonella enterica serovar Typhimurium. It is shown that Arg-11 and Gly-232 are key residues for thermodynamic stability of the enzyme, and that Asp-201 is important for both catalysis and allosteric regulation. A comparison of the amino acid sequence of UMP kinases from several prokaryotes showed that these were conserved residues. Discussion on the enzyme activity level in relation to bacterial viability is also presented.
authors.affiliation: Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Landais
authors.affiliation: Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Evrin
authors.affiliation: Plate-forme 3 Protéomique, Institut Pasteur, 75724 Paris Cedex 15, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Laurent-Winter
authors.affiliation: Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
authors.forename: Octavian
authors.initials: O
authors.lastname: Bârzu
authors.affiliation: Department of Chemistry and Biochemistry, University of Regina, Regina, Saskatchewan, Canada S4S 0A2.
authors.forename: Rod A
authors.initials: RA
authors.lastname: Kelln
mesh_terms: D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D016153:Genes, Suppressor; D006358:Hot Temperature; D006801:Humans; D009154:Mutation; D009703:Nucleoside-Phosphate Kinase / Q000737:chemistry* / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000201:enzymology* / Q000235:genetics; D013329:Structure-Activity Relationship; D014166:Transferases / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; C078379:pyrH protein, E coli; D014166:Transferases; C023276:uridine monophosphate kinase; D009703:Nucleoside-Phosphate Kinase