Structure-function relationships of UMP kinases from pyrH mutants of Gram-negative bacteria

• Published in: Microbiology (Society for General Microbiology) 2004-07, Vol.150 (7), p.2153-2159
• Main Authors: Sakamoto, Hiroshi, Landais, Stephanie, Evrin, Cecile, Laurent-Winter, Christine, Barzu, Octavian, Kelln, Rod A
• Format: Article
• Language: English
• Subjects: Bacterial plant pathogens; Bacteriology; Biological and medical sciences; Enzyme Stability; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli - growth & development; Escherichia coli Proteins - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Genes, Suppressor; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Hot Temperature; Humans; Microbiology; Miscellaneous; Mutation; Mycology; Nucleoside-Phosphate Kinase - chemistry; Nucleoside-Phosphate Kinase - metabolism; Phytopathology. Animal pests. Plant and forest protection; Salmonella enterica; Salmonella typhimurium - enzymology; Salmonella typhimurium - genetics; Structure-Activity Relationship; Transferases - genetics
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.26996-0

1 Laboratoire de Chimie Structurale des Macromolécules, Institut Pasteur, 75724 Paris Cedex 15, France 2 Plate-forme 3 Protéomique, Institut Pasteur, 75724 Paris Cedex 15, France 3 Department of Chemistry and Biochemistry, University of Regina, Regina, Saskatchewan, Canada S4S 0A2 Correspondence Hiroshi Sakamoto hiroshi{at}pasteur.fr 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. Abbreviations: ATCase, aspartate transcarbamoylase; 5-FOA, 5-fluoroorotic acid