title: New class of IMP cyclohydrolases in Methanococcus jannaschii.
abstract: The enzyme responsible for observed IMP cyclohydrolase activity in Methanococcus jannaschii was purified and sequenced: its genetic locus was found to correspond to gene MJ0626. The MJ0626 gene was cloned, and its protein product was expressed in Escherichia coli and shown to catalyze the cyclization of 5-formylamidoimidazole-4-carboxamide ribonucleotide to IMP. The enzyme has no sequence similarity to known enzymes, and its catalytic properties appear distinct from any characterized IMP cyclohydrolase. The purO gene for the enzyme is currently found only in the domain Archaea.
authors.affiliation: Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0308, USA.
authors.forename: Marion
authors.initials: M
authors.lastname: Graupner
authors.forename: Huimin
authors.initials: H
authors.lastname: Xu
authors.forename: Robert H
authors.initials: RH
authors.lastname: White
mesh_terms: D019641:DNA, Archaeal / Q000235:genetics; D019766:Genes, Archaeal; D017017:Methanococcus / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D009709:Nucleotide Deaminases / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D019641:DNA, Archaeal; D009709:Nucleotide Deaminases; C021436:IMP cyclohydrolase