The F420H2:heterodisulfide oxidoreductase system from Methanosarcina species

Bäumer, Sebastian; Murakami, Eisuke; Brodersen, Jens; Gottschalk, Gerhard; Ragsdale, Stephen W.; Deppenmeier, Uwe

doi:10.1016/s0014-5793(98)00555-9

Cited by 43 publications

(20 citation statements)

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“…Reducing equivalents from F 420 H 2 were transferred to 2-OHphenazine by the membrane-bound F 420 H 2 dehydrogenase. Furthermore, the heterodisulfide reductase present in the cytoplasmic membrane was able to use reduced 2-OH-phenazine as electron donor for the reduction of CoB-S-S-CoM (10).…”

Section: Resultsmentioning

confidence: 99%

“…Because the gene products of the remaining fpo genes were not found in the homogeneous protein preparation, it is most likely that only a subcomplex of the F 420 H 2 dehydrogenase was purified and that the other subunits were lost during purification. However, the core enzyme composed of FpoB, C, D, F, and I showed catalytic activity with F 420 H 2 as electron donor and several artificial dyes as electron acceptors (10).…”

Section: Figmentioning

confidence: 96%

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The F420H2 Dehydrogenase fromMethanosarcina mazei Is a Redox-driven Proton Pump Closely Related to NADH Dehydrogenases

Bäumer¹,

Ide²,

Jacobi³

et al. 2000

Journal of Biological Chemistry

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113

109

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The F 420 H 2 dehydrogenase is part of the energy conserving electron transport system of the methanogenic archaeon Methanosarcina mazei Gö 1. Here it is shown that cofactor F 420 H 2 -dependent reduction of 2-hydroxyphenazine as catalyzed by the membrane-bound enzyme is coupled to proton translocation across the cytoplasmic membrane, exhibiting a stoichiometry of 0.9 H Methanosarcina mazei strain Gö1 is a strictly anaerobic methanogenic archaeon that converts a limited number of simple substrates (H 2 ϩ CO 2 , methanol, methylamines, and acetate) to methane. 2-methylthioethanesulfonate is the central intermediate in all methanogenic pathways and is reductively demethylated to methane catalyzed by the 2-methylthioethanesulfonate reductase. The two electrons required for the reduction are derived from 7-mercaptoheptanoylthreonine phosphate, resulting in the formation of a heterodisulfide (CoB-S-S-CoM) 1 of 2-mercaptoethanesulfonate (HS-CoM) and 7-mercaptoheptanoylthreonine phosphate (HS-CoB) (1). An energyconserving step in the metabolism of methanogens is the reduction of CoB-S-S-CoM with either molecular hydrogen or reduced coenzyme F 420 . In recent years, the membrane-bound electron transfer of M. mazei Gö1 has been analyzed in detail, resulting in the discovery of two proton translocating systems referred to as H 2 :heterodisulfide oxidoreductase and F 420 H 2 : heterodisulfide oxidoreductase, respectively (2).During growth on methylated substrates, part of the methyl groups of the substrates is oxidized to CO 2 , and reducing equivalents are transferred to F 420 . The reduced cofactor (F 420 H 2 ) is reoxidized by the above-mentioned membrane-bound electron transport system consisting of an F 420 H 2 dehydrogenase and a heterodisulfide reductase. The transfer of electrons between the enzymes is most likely mediated by methanophenazine, a hydrophobic cofactor that has been isolated from the cytoplasmic membrane of M. mazei Gö1. The overall process has been shown to be competent in driving proton translocation across the cytoplasmic membrane (3). The resulting electrochemical proton gradient is the driving force for ATP synthesis from ADP ϩ P i catalyzed by an A 1 A 0 -type ATP synthase (2, 4).The F 420 H 2 dehydrogenase with a molecular mass of 115 kDa has been purified from M. mazei Gö1 and contains iron-sulfur clusters and FAD (5). The isolated enzyme is very similar to the corresponding protein from Methanolobus tindarius (6) and is composed of five different subunits with molecular masses of 40, 37, 22, 20, and 17 kDa. A F 420 H 2 dehydrogenase has also been purified form the sulfate-reducing archaeon Archaeoglobus fulgidus (7).In this report the gene locus encoding the F 420 H 2 dehydrogenase on the M. mazei genome is described. Furthermore, it is shown that the corresponding enzyme is a novel proton pump ¶ To whom correspondence should be addressed. Fax: 49-551-393793; E-mail: udeppen@gwdg.de. 1 The abbreviations used are: CoB-S-S-CoM, heterodisulfide of HSCoM and HS-CoB; HS-CoM, 2-mercaptoethansulfona...

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Section: Resultsmentioning

confidence: 99%

Section: Figmentioning

confidence: 96%

The F420H2 Dehydrogenase fromMethanosarcina mazei Is a Redox-driven Proton Pump Closely Related to NADH Dehydrogenases

Bäumer¹,

Ide²,

Jacobi³

et al. 2000

Journal of Biological Chemistry

Self Cite

113

109

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“…A F 420 H 2 dehydrogenase has also been isolated from the sulfate‐reducing archaeon Archaeoglobus fulgidus [22]. Recently, the F 420 H 2 :heterodisulfide oxidoreductase could be reconstituted by the combination of purified F 420 H 2 dehydrogenase from Ms. mazei Gö1, 2‐OH‐phenazine and purified heterodisulfide reductase from Ms. thermophila [23].…”

Section: Redox‐driven Ion Translocation In Methylotrophic Methanogensmentioning

confidence: 99%

Novel reactions involved in energy conservation by methanogenic archaea

1999

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Methanogenic archaea of the order Methanosarcinales which utilize C(1) compounds such as methanol, methylamines or H(2)+CO(2), employ two novel membrane-bound electron transport systems generating an electrochemical proton gradient: the H(2):heterodisulfide oxidoreductase and the F(420)H(2):heterodisulfide oxidoreductase. The systems are composed of the heterodisulfide reductase and either a membrane-bound hydrogenase or a F(420)H(2) dehydrogenase which is functionally homologous to the proton-translocating NADH dehydrogenase. Cytochromes and the novel electron carrier methanophenazine are also involved. In addition, the methyl-H(4)MPT:HS-CoM methyltransferase is bioenergetically relevant. The enzyme couples methyl group transfer with the translocation of sodium ions and seems to be present in all methanogens. The proton-translocating systems with the participation of cytochromes and methanophenazine have been found so far only in the Methanosarcinales.

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“…The F 420 dehydrogenases from Methanosarcina mazei (7), Methanolobus tindarius (8), and Archaeoglobus fulgidus (9) have been isolated and shown to contain Fe-S clusters and FAD. The direct electron donor for HDR appears to be a membrane-bound cofactor, methanophenazine (MPhen) (10). This cofactor has been isolated from membranes of M. mazei strain Gö1 (11) and Methanosarcina thermophila.…”

mentioning

confidence: 99%

“…2 It has a 25-carbon isoprenoid chain attached to position 2 of phenazine via an ether bond, which makes it insoluble in aqueous solution (11). The 2-hydroxyphenazine (HPhen) derivative is a suitable water-soluble substitute for MPhen that can accept electrons from F 420 H 2 and can donate electrons to the purified HDR from M. thermophila (10). Electron transfer from F 420 H 2 to HPhen results in the translocation of two protons per two electrons transferred (12).…”

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confidence: 99%