A methenyl tetrahydromethanopterin cyclohydrolase and a methenyl tetrahydrofolate cyclohydrolase in Methylobacterium extorquens AM1
نویسندگان
چکیده
منابع مشابه
The 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 کاملDevelopment of an insertional expression vector system for Methylobacterium extorquens AM1 and generation of null mutants lacking mtdA and/or fch.
Over the past few years, the genetic 'toolkit' available for use with Methylobacterium extorquens AM1 has expanded significantly. Here a further advance is presented and demonstrated, an insertional expression system that allows expression of genes from a stable, unmarked chromosomal locus. This system has been used to better understand the role of the tetrahydrofolate (H4F) pathway in methylot...
متن کاملDistribution of tetrahydromethanopterin-dependent enzymes in methylotrophic bacteria and phylogeny of methenyl tetrahydromethanopterin cyclohydrolases.
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 ...
متن کاملBiochemical 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...
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ژورنال
عنوان ژورنال: European Journal of Biochemistry
سال: 1999
ISSN: 0014-2956,1432-1033
DOI: 10.1046/j.1432-1327.1999.00291.x