Characterization of Two Methanopterin Biosynthesis Mutants of Methylobacterium extorquens AM1 by Use of a Tetrahydromethanopterin Bioassay
نویسندگان
چکیده
منابع مشابه
Characterization 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 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 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 کاملFormaldehyde-detoxifying role of the tetrahydromethanopterin-linked pathway in Methylobacterium extorquens AM1.
The facultative methylotroph Methylobacterium extorquens AM1 possesses two pterin-dependent pathways for C(1) transfer between formaldehyde and formate, the tetrahydrofolate (H(4)F)-linked pathway and the tetrahydromethanopterin (H(4)MPT)-linked pathway. Both pathways are required for growth on C(1) substrates; however, mutants defective for the H(4)MPT pathway reveal a unique phenotype of bein...
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.186.5.1565-1570.2004