title: Distribution of tetrahydromethanopterin-dependent enzymes in methylotrophic bacteria and phylogeny of methenyl tetrahydromethanopterin cyclohydrolases.
abstract: The methylotrophic proteobacterium Methylobacterium extorquens AM1 possesses tetrahydromethanopterin (H(4)MPT)-dependent enzymes, which are otherwise specific to methanogenic and sulfate-reducing archaea and which have been suggested to be involved in formaldehyde oxidation to CO(2) in M. extorquens AM1. The distribution of H(4)MPT-dependent enzyme activities in cell extracts of methylotrophic bacteria from 13 different genera are reported. H(4)MPT-dependent activities were detected in all of the methylotrophic and methanotrophic proteobacteria tested that assimilate formaldehyde by the serine or ribulose monophosphate pathway. H(4)MPT-dependent activities were also found in autotrophic Xanthobacter strains. However, no H(4)MPT-dependent enzyme activities could be detected in other autotrophic alpha-proteobacteria or in gram-positive methylotrophic bacteria. Genes encoding methenyl H(4)MPT cyclohydrolase (mch genes) were cloned and sequenced from several proteobacteria. Bacterial and archaeal Mch sequences have roughly 35% amino acid identity and form distinct groups in phylogenetic analysis.
authors.affiliation: Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Vorholt
authors.forename: L
authors.initials: L
authors.lastname: Chistoserdova
authors.forename: S M
authors.initials: SM
authors.lastname: Stolyar
authors.forename: R K
authors.initials: RK
authors.lastname: Thauer
authors.forename: M E
authors.initials: ME
authors.lastname: Lidstrom
mesh_terms: D000595:Amino Acid Sequence; D000619:Aminohydrolases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D017931:DNA Primers; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D007700:Kinetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011622:Pterins / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: C040753:5,10-methenyl-5,6,7,8-tetrahydromethanopterin; D017931:DNA Primers; D011622:Pterins; D011994:Recombinant Proteins; D000619:Aminohydrolases; C050675:methenyltetrahydromethanopterin cyclohydrolase