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- Name help_outline 1,4,5,6-tetrahydro-6-oxonicotinate Identifier CHEBI:57777 Charge -1 Formula C6H6NO3 InChIKeyhelp_outline SDKCWSUZEUBWLP-UHFFFAOYSA-M SMILEShelp_outline [O-]C(=O)C1=CNC(=O)CC1 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,204 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 2-formylglutarate Identifier CHEBI:58776 Charge -2 Formula C6H6O5 InChIKeyhelp_outline NMUKFRCHLYPKSR-UHFFFAOYSA-L SMILEShelp_outline [H]C(=O)C(CCC([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NH4+ Identifier CHEBI:28938 (CAS: 14798-03-9) help_outline Charge 1 Formula H4N InChIKeyhelp_outline QGZKDVFQNNGYKY-UHFFFAOYSA-O SMILEShelp_outline [H][N+]([H])([H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 528 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:17209 | RHEA:17210 | RHEA:17211 | RHEA:17212 | |
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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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The crystal structure of enamidase: a bifunctional enzyme of the nicotinate catabolism.
Kress D., Alhapel A., Pierik A.J., Essen L.O.
The hydrolysis of 1,4,5,6-tetrahydro-6-oxonicotinate to 2-formylglutarate is a central step in the catabolism of nicotinate in several Clostridia and Proteobacteria. This reaction is catalyzed by the novel enzyme enamidase, a new member of the amidohydrolase superfamily as indicated by its unique ... >> More
The hydrolysis of 1,4,5,6-tetrahydro-6-oxonicotinate to 2-formylglutarate is a central step in the catabolism of nicotinate in several Clostridia and Proteobacteria. This reaction is catalyzed by the novel enzyme enamidase, a new member of the amidohydrolase superfamily as indicated by its unique reaction, sequence relationship, and the stoichiometric binding of iron and zinc. A hallmark of enamidase is its capability to catalyze a two-step reaction: the initial decyclization of 1,4,5,6-tetrahydro-6-oxonicotinate leading to 2-(enamine)glutarate followed by an additional hydrolysis step yielding (S)-2-formylglutarate. Here, we present the crystal structure of enamidase from Eubacterium barkeri at 1.9 A resolution, providing a structural basis for catalysis and suggesting a mechanism for its exceptional activity and enantioselectivity. The enzyme forms a 222-symmetric tetramer built up by a dimer of dimers. Each enamidase monomer consists of a composite beta-sandwich domain and an (alpha/beta)(8)-TIM-barrel domain harboring the active site. With its catalytic binuclear metal center comprising both zinc and iron ions, enamidase represents a special case of subtype II amidohydrolases. << Less
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Molecular and functional analysis of nicotinate catabolism in Eubacterium barkeri.
Alhapel A., Darley D.J., Wagener N., Eckel E., Elsner N., Pierik A.J.
The anaerobic soil bacterium Eubacterium barkeri catabolizes nicotinate to pyruvate and propionate via a unique fermentation. A full molecular characterization of nicotinate fermentation in this organism was accomplished by the following results: (i) A 23.2-kb DNA segment with a gene cluster encod ... >> More
The anaerobic soil bacterium Eubacterium barkeri catabolizes nicotinate to pyruvate and propionate via a unique fermentation. A full molecular characterization of nicotinate fermentation in this organism was accomplished by the following results: (i) A 23.2-kb DNA segment with a gene cluster encoding all nine enzymes was cloned and sequenced, (ii) two chiral intermediates were discovered, and (iii) three enzymes were found, completing the hitherto unknown part of the pathway. Nicotinate dehydrogenase, a (nonselenocysteine) selenium-containing four-subunit enzyme, is encoded by ndhF (FAD subunit), ndhS (2 x [2Fe-2S] subunit), and by the ndhL/ndhM genes. In contrast to all enzymes of the xanthine dehydrogenase family, the latter two encode a two-subunit molybdopterin protein. The 6-hydroxynicotinate reductase, catalyzing reduction of 6-hydroxynicotinate to 1,4,5,6-tetrahydro-6-oxonicotinate, was purified and shown to contain a covalently bound flavin cofactor, one [2Fe-2S](2+/1+) and two [4Fe-4S](2+/1+) clusters. Enamidase, a bifunctional Fe-Zn enzyme belonging to the amidohydrolase family, mediates hydrolysis of 1,4,5,6-tetrahydro-6-oxonicotinate to ammonia and (S)-2-formylglutarate. NADH-dependent reduction of the latter to (S)-2-(hydroxymethyl)glutarate is catalyzed by a member of the 3-hydroxyisobutyrate/phosphogluconate dehydrogenase family. A [4Fe-4S]-containing serine dehydratase-like enzyme is predicted to form 2-methyleneglutarate. After the action of the coenzyme B(12)-dependent 2-methyleneglutarate mutase and 3-methylitaconate isomerase, an aconitase and isocitrate lyase family pair of enzymes, (2R,3S)-dimethylmalate dehydratase and lyase, completes the pathway. Genes corresponding to the first three enzymes of the E. barkeri nicotinate catabolism were identified in nine Proteobacteria. << Less
Proc. Natl. Acad. Sci. U.S.A. 103:12341-12346(2006) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.