title: Three new Nudix hydrolases from Escherichia coli.
abstract: Three members of the Nudix (nucleoside diphosphate X) hydrolase superfamily have been cloned from Escherichia coli MG1655 and expressed. The proteins have been purified and identified as enzymes active on nucleoside diphosphate derivatives with the following specificities. Orf141 (yfaO) is a nucleoside triphosphatase preferring pyrimidine deoxynucleoside triphosphates. Orf153 (ymfB) is a nonspecific nucleoside tri- and diphosphatase and atypically releases inorganic orthophosphate from triphosphates instead of pyrophosphate. Orf191 (yffH) is a highly active GDP-mannose pyrophosphatase. All three enzymes require a divalent cation for activity and are optimally active at alkaline pH, characteristic of the Nudix hydrolase superfamily. The question of whether or not Orf1.9 (wcaH) is a bona fide member of the Nudix hydrolase superfamily is discussed.
authors.affiliation: Department of Biology and The McCollum Pratt Institute, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: Wenlian
authors.initials: W
authors.lastname: Xu
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Dunn
authors.forename: Suzanne F
authors.initials: SF
authors.lastname: O'handley
authors.forename: Denise L
authors.initials: DL
authors.lastname: Smith
authors.forename: Maurice J
authors.initials: MJ
authors.lastname: Bessman
mesh_terms: D000595:Amino Acid Sequence; D002412:Cations; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics*; D006868:Hydrolysis; D007700:Kinetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D005810:Multigene Family; D011755:Pyrophosphatases / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D000096964:Nudix Hydrolases
chemical_list: D002412:Cations; D029968:Escherichia coli Proteins; D011755:Pyrophosphatases; D000096964:Nudix Hydrolases; C513849:YfaO protein, E coli; C513852:YffH protein, E coli; C513850:YmfB protein, E coli