Biochemical Characterization of a Dihydromethanopterin Reductase Involved in Tetrahydromethanopterin Biosynthesis in Methylobacterium extorquens AM1
نویسندگان
چکیده
منابع مشابه
Biochemical characterization of a dihydromethanopterin reductase involved in tetrahydromethanopterin biosynthesis in Methylobacterium extorquens AM1.
During growth on one-carbon (C1) compounds, the aerobic alpha-proteobacterium Methylobacterium extorquens AM1 synthesizes the tetrahydromethanopterin (H4MPT) derivative dephospho-H4MPT as a C1 carrier in addition to tetrahydrofolate. The enzymes involved in dephospho-H4MPT biosynthesis have not been identified in bacteria. In archaea, the final step in the proposed pathway of H4MPT biosynthesis...
متن کاملCharacterization of two methanopterin biosynthesis mutants of Methylobacterium extorquens AM1 by use of a tetrahydromethanopterin bioassay.
An enzymatic assay was developed to measure tetrahydromethanopterin (H(4)MPT) levels in wild-type and mutant cells of Methylobacterium extorquens AM1. H(4)MPT was detectable in wild-type cells but not in strains with a mutation of either the orf4 or the dmrA gene, suggesting a role for these two genes in H(4)MPT biosynthesis. The protein encoded by orf4 catalyzed the reaction of ribofuranosylam...
متن کاملThe NADP-dependent methylene tetrahydromethanopterin dehydrogenase in Methylobacterium extorquens AM1.
An NADP-dependent methylene tetrahydromethanopterin (H4MPT) dehydrogenase has recently been proposed to be involved in formaldehyde oxidation to CO2 in Methylobacterium extorquens AM1. We report here on the purification of this novel enzyme to apparent homogeneity. Via the N-terminal amino acid sequence, it was identified to be the mtdA gene product. The purified enzyme catalyzed the dehydrogen...
متن کاملNovel methylotrophy genes of Methylobacterium extorquens AM1 identified by using transposon mutagenesis including a putative dihydromethanopterin reductase.
Ten novel methylotrophy genes of the facultative methylotroph Methylobacterium extorquens AM1 were identified from a transposon mutagenesis screen. One of these genes encodes a product having identity with dihydrofolate reductase (DHFR). This mutant has a C(1)-defective and methanol-sensitive phenotype that has previously only been observed for strains defective in tetrahydromethanopterin (H(4)...
متن کاملElucidation of the role of the methylene-tetrahydromethanopterin dehydrogenase MtdA in the tetrahydromethanopterin-dependent oxidation pathway in Methylobacterium extorquens AM1.
The methylotroph Methylobacterium extorquens AM1 oxidizes methanol and methylamine to formaldehyde and subsequently to formate, an intermediate that serves as the branch point between assimilation (formation of biomass) and dissimilation (oxidation to CO₂). The oxidation of formaldehyde to formate is dephosphotetrahydromethanopterin (dH₄MPT) dependent, while the assimilation of carbon into biom...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 2004
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.186.7.2068-2073.2004