title: Comparative modelling and immunochemical reactivity of Escherichia coli UMP kinase.
abstract: Bacterial UMP kinases do not exhibit any sequence homology with other nucleoside monophosphate kinases described so far, and appear under oligomeric forms, submitted to complex regulation by nucleotides. We propose here a structural model of UMP kinase from Escherichia coli based on the conservation of the fold of carbamate kinase whose crystal structure was recently solved. Despite sequence identity of only 18% over 203 amino acids, alignment of UMP kinase from E. coli with carbamate kinase from Enterococcus faecalis by hydrophobic cluster analysis and threading suggested the conservation of the overall structure, except for a small subdomain (absent in UMP kinase). The modelled dimer suggested conservation of the dimer interface observed in carbamate kinase while interaction of UMP kinase with a monoclonal antibody (Mab 44-2) suggests a three in-plane dimer subunit arrangement. The model was analyzed in light of various modified forms of UMP kinase obtained by site-directed mutagenesis.
authors.affiliation: Centre de Biochimie Structurale, Faculté de Pharmacie, Université de Montpellier I, 34000 Montpellier, France. labesse@cbs.cnrs.fr
authors.forename: Gilles
authors.initials: G
authors.lastname: Labesse
authors.forename: Nadia
authors.initials: N
authors.lastname: Bucurenci
authors.forename: Dominique
authors.initials: D
authors.lastname: Douguet
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Landais
authors.forename: Cristina
authors.initials: C
authors.lastname: Gagyi
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Gilles
authors.forename: Octavian
authors.initials: O
authors.lastname: Bârzu
mesh_terms: D000595:Amino Acid Sequence; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009703:Nucleoside-Phosphate Kinase / Q000737:chemistry*; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: C023276:uridine monophosphate kinase; D009703:Nucleoside-Phosphate Kinase