title: Purification and characterization of the methylene tetrahydromethanopterin dehydrogenase MtdB and the methylene tetrahydrofolate dehydrogenase FolD from Hyphomicrobium zavarzinii ZV580.
abstract: Recently, it has been shown that heterotrophic methylotrophic Proteobacteria contain tetrahydrofolate (H(4)F)- and tetrahydromethanopterin (H(4)MPT)-dependent enzymes. Here we report on the purification of two methylene tetrahydropterin dehydrogenases from the methylotroph Hyphomicrobium zavarzinii ZV580. Both dehydrogenases are composed of one type of subunit of 31 kDa. One of the dehydrogenases is NAD(P)-dependent and specific for methylene H(4)MPT (specific activity: 680 U/mg). Its N-terminal amino acid sequence showed sequence identity to NAD(P)-dependent methylene H(4)MPT dehydrogenase MtdB from Methylobacterium extorquens AM1. The second dehydrogenase is specific for NADP and methylene H(4)F (specific activity: 180 U/mg) and also exhibits methenyl H(4)F cyclohydrolase activity. Via N-terminal amino acid sequencing this dehydrogenase was identified as belonging to the classical bifunctional methylene H(4)F dehydrogenases/cyclohydrolases (FolD) found in many bacteria and eukarya. Apparently, the occurrence of methylene tetrahydrofolate and methylene tetrahydromethanopterin dehydrogenases is not uniform among different methylotrophic alpha-Proteobacteria. For example, FolD was not found in M. extorquens AM1, and the NADP-dependent methylene H(4)MPT dehydrogenase MtdA was present in the bacterium that also shows H(4)F activity.
authors.affiliation: Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Strasse, 35043 Marburg, Germany.
authors.forename: Meike
authors.initials: M
authors.lastname: Goenrich
authors.forename: Jan
authors.initials: J
authors.lastname: Bursy
authors.forename: Eva
authors.initials: E
authors.lastname: Hübner
authors.forename: Dietmar
authors.initials: D
authors.lastname: Linder
authors.forename: Arnold C
authors.initials: AC
authors.lastname: Schwartz
authors.forename: Julia A
authors.initials: JA
authors.lastname: Vorholt
mesh_terms: D000595:Amino Acid Sequence; D019143:Evolution, Molecular; D020582:Hyphomicrobium / Q000201:enzymology* / Q000235:genetics; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP) / Q000032:analysis* / Q000302:isolation & purification* / Q000502:physiology; D008969:Molecular Sequence Data; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000032:analysis* / Q000302:isolation & purification* / Q000502:physiology; D016415:Sequence Alignment
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP); C047126:methylenetetrahydromethanopterin dehydrogenase