Structure-function relationships of UMP kinases from pyrH mutants of Gram-negative bacteria.
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.
Sakamoto
Hiroshi
H
Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
Landais
Stéphanie
S
Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
Evrin
Cécile
C
Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
Laurent-Winter
Christine
C
Plate-forme 3 Protéomique, Institut Pasteur, 75724 Paris Cedex 15, France.
Bârzu
Octavian
O
Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France.
Kelln
Rod A
RA
Department of Chemistry and Biochemistry, University of Regina, Regina, Saskatchewan, Canada S4S 0A2.
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*
D029968:Escherichia coli Proteins; C078379:pyrH protein, E coli; D014166:Transferases; C023276:uridine monophosphate kinase; D009703:Nucleoside-Phosphate Kinase