5,6,7,8-Tetrahydromethanopterin-dependent enzymes involved in methanogenesis |
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Authors: | Jan T. Keltjens,Ben W. te,Brö mmelstroet ,Servé W.M. Kengen,Chris van der,Drift Godfried D. Vogels |
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Affiliation: | Department of Microbiology, University of Nijmegen, Nijmegen, The Netherlands |
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Abstract: | Abstract In the process of methanogenesis, 5,6,7,8-tetrahydromethanopterin (H4MPT) is the carrier of the C1 unit at the formyl through methyl state of reduction. By the transfer of a formyl group from formylmethanofuran, 5-formyl- and 10-formyl-H4MPT are formed in hydrogenotrophic and methylotrophic organisms, respectively. Cyclohydrolysis of the 5- and 10-formyl derivatives then yields 5,10-methenyl-H4MPT, which is reduced in two subsequent coenzyme F420-dependent reactions to 5-methyl-H4MPT. Following the transfer of the methyl group to coenzyme M, the substrate of the terminal step in methanogenesis, methylcoenzyme M, is produced. In this paper properties of the enzymes catalyzing the individual H4MPT-dependent reactions are discussed. |
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Keywords: | 5,6,7,8-Tetrahydromethanopterin Coenzyme F420 Methanogenesis Methanobacterium thermoautotrophicum Methanosarcina barkeri |
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