title: MazG, a nucleoside triphosphate pyrophosphohydrolase, interacts with Era, an essential GTPase in Escherichia coli.
abstract: Era is an essential GTPase in Escherichia coli, and Era has been implicated in a number of cellular functions. Homologues of Era have been identified in various bacteria and some eukaryotes. Using the era gene as bait in the yeast two-hybrid system to screen E. coli genomic libraries, we discovered that Era interacts with MazG, a protein of unknown function which is highly conserved among bacteria. The direct interaction between Era and MazG was also confirmed in vitro, being stronger in the presence of GDP than in the presence of GTPgammaS. MazG was characterized as a nucleoside triphosphate pyrophosphohydrolase which can hydrolyze all eight of the canonical ribo- and deoxynucleoside triphosphates to their respective monophosphates and PP(i), with a preference for deoxynucleotides. A mazG deletion strain of E. coli was constructed by replacing the mazG gene with a kanamycin resistance gene. Unlike mutT, a gene for another conserved nucleotide triphosphate pyrophosphohydrolase that functions as a mutator gene, the mazG deletion did not result in a mutator phenotype in E. coli.
authors.affiliation: Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.forename: Masayori
authors.initials: M
authors.lastname: Inouye
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D011755:Pyrophosphatases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016601:RNA-Binding Proteins; D016415:Sequence Alignment; D013379:Substrate Specificity; D020798:Two-Hybrid System Techniques
chemical_list: D029968:Escherichia coli Proteins; D016601:RNA-Binding Proteins; C068027:era protein, E coli; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D011755:Pyrophosphatases; C021895:nucleoside triphosphate pyrophosphatase