Enzymes
| UniProtKB help_outline | 2 proteins |
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- Name help_outline 5,6,7,8-tetrahydromethanopterin Identifier CHEBI:58103 Charge -3 Formula C30H42N6O16P InChIKeyhelp_outline SCBIBGUJSMHIAI-LHIIQLEZSA-K SMILEShelp_outline [H][C@]1(Nc2c(N[C@H]1C)nc(N)[nH]c2=O)[C@@H](C)Nc1ccc(C[C@H](O)[C@H](O)[C@H](O)CO[C@H]2O[C@H](COP([O-])(=O)O[C@@H](CCC([O-])=O)C([O-])=O)[C@@H](O)[C@H]2O)cc1 2D coordinates Mol file for the small molecule Search links Involved in 9 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline A Identifier CHEBI:13193 Charge Formula R SMILEShelp_outline * 2D coordinates Mol file for the small molecule Search links Involved in 2,870 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 7,8-dihydromethanopterin Identifier CHEBI:72788 Charge -3 Formula C30H40N6O16P InChIKeyhelp_outline WTMBWYHMZCVPRJ-WJBIZLLUSA-K SMILEShelp_outline C[C@@H](Nc1ccc(C[C@H](O)[C@H](O)[C@H](O)CO[C@H]2O[C@H](COP([O-])(=O)O[C@@H](CCC([O-])=O)C([O-])=O)[C@@H](O)[C@H]2O)cc1)C1=Nc2c(N[C@H]1C)nc(N)[nH]c2=O 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline AH2 Identifier CHEBI:17499 Charge 0 Formula RH2 SMILEShelp_outline *([H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 2,799 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:42804 | RHEA:42805 | RHEA:42806 | RHEA:42807 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Discovery and characterization of the first archaeal dihydromethanopterin reductase, an iron-sulfur flavoprotein from Methanosarcina mazei.
Wang S., Tiongson J., Rasche M.E.
The microbial production of methane by methanogenic archaea is dependent on the synthesis of the pterin-containing cofactor tetrahydromethanopterin (H4MPT). The enzyme catalyzing the last step of H4MPT biosynthesis (dihydromethanopterin reductase) has not previously been identified in methane-prod ... >> More
The microbial production of methane by methanogenic archaea is dependent on the synthesis of the pterin-containing cofactor tetrahydromethanopterin (H4MPT). The enzyme catalyzing the last step of H4MPT biosynthesis (dihydromethanopterin reductase) has not previously been identified in methane-producing microorganisms. Previous complementation studies with the methylotrophic bacterium Methylobacterium extorquens have indicated that an uncharacterized archaeal-flavoprotein-like flavoprotein (AfpA) from Methylobacillus flagellatus or Burkholderia xenovorans can replace the activity of a phylogenetically unrelated bacterial dihydromethanopterin reductase (DmrA). We propose that MM1854, a homolog of AfpA from Methanosarcina mazei, catalyzes the last step of H4MPT biosynthesis in methane-producing microorganisms. To test this hypothesis, a six-histidine (His6)-tagged version of MM1854 was produced. Bioinformatic analysis revealed the presence of one flavin mononucleotide (FMN)-binding site and two iron-sulfur cluster sites, consistent with an oxidoreductase enzyme. Purified His6-MM1854 occurred as a homodimer of 29-kDa subunits, and the UV-visible spectrum of the purified protein showed absorbance peaks at 380 and 460 nm, characteristic of oxidized FMN. NAD(P)H was incapable of directly reducing the flavin cofactor, but dithionite eliminated the FMN peaks, indicating successful electron transfer to MM1854. An electron transfer system of NADPH, spinach NADPH-ferredoxin oxidoreductase, and ferredoxin could also reduce the FMN peaks. A newly developed assay indicated that dithiothreitol-reduced MM1854 could transfer electrons to dihydromethanopterin. This assay was also effective with a heat-stable DmrX analog from Methanocaldococcus jannaschii (MJ0208). These results provide the first biochemical evidence that MM1854 and MJ0208 function as archaeal dihydromethanopterin reductases (DmrX) and that ferredoxin may serve as an electron donor. << Less