Enzymes
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- Name help_outline iminosuccinate Identifier CHEBI:77875 Charge -1 Formula C4H4NO4 InChIKeyhelp_outline NMUOATVLLQEYHI-UHFFFAOYSA-M SMILEShelp_outline [O-]C(=O)CC(=[NH2+])C([O-])=O 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 dihydroxyacetone phosphate Identifier CHEBI:57642 (Beilstein: 4428349) help_outline Charge -2 Formula C3H5O6P InChIKeyhelp_outline GNGACRATGGDKBX-UHFFFAOYSA-L SMILEShelp_outline C(CO)(COP([O-])(=O)[O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 41 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline quinolinate Identifier CHEBI:29959 Charge -2 Formula C7H3NO4 InChIKeyhelp_outline GJAWHXHKYYXBSV-UHFFFAOYSA-L SMILEShelp_outline [O-]C(=O)c1cccnc1C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1,002 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (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 6,264 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,521 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:25888 | RHEA:25889 | RHEA:25890 | RHEA:25891 | |
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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 [4Fe-4S] cluster of quinolinate synthase from Escherichia coli: investigation of cluster ligands.
Rousset C., Fontecave M., Ollagnier de Choudens S.
Nicotinamide adenine dinucleotide (NAD) derives from quinolinic acid which is synthesized in Escherichia coli from l-aspartate and dihydroxyacetone phosphate through the concerted action of l-aspartate oxidase and the [4Fe-4S] quinolinate synthase (NadA). Here, we addressed the question of the ide ... >> More
Nicotinamide adenine dinucleotide (NAD) derives from quinolinic acid which is synthesized in Escherichia coli from l-aspartate and dihydroxyacetone phosphate through the concerted action of l-aspartate oxidase and the [4Fe-4S] quinolinate synthase (NadA). Here, we addressed the question of the identity of the cluster ligands. We performed in vivo complementation experiments as well as enzymatic, spectroscopic and structural in vitro studies using wild-type vs. Cys-to-Ala mutated NadA proteins. These studies reveal that only three cysteine residues, the conserved Cys113, Cys200 and Cys297, are ligands of the cluster. This result is in contrast to the previous proposal that pointed the three cysteines of the C(291)XXC(294)XXC(297) motif. Interestingly, we demonstrated that Cys291 and Cys294 form a disulfide bridge and are important for activity. << Less
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Quinolinate synthetase, an iron-sulfur enzyme in NAD biosynthesis.
Ollagnier-de Choudens S., Loiseau L., Sanakis Y., Barras F., Fontecave M.
Nicotinamide adenine dinucleotide (NAD) plays a crucial role as a cofactor in numerous essential redox biological reactions. NAD derives from quinolinic acid which is synthesized in Escherichia coli from L-aspartate and dihydroxyacetone phosphate (DHAP) as the result of the concerted action of two ... >> More
Nicotinamide adenine dinucleotide (NAD) plays a crucial role as a cofactor in numerous essential redox biological reactions. NAD derives from quinolinic acid which is synthesized in Escherichia coli from L-aspartate and dihydroxyacetone phosphate (DHAP) as the result of the concerted action of two enzymes, L-aspartate oxidase (NadB) and quinolinate synthetase (NadA). We report here the characterization of NadA protein from E. coli. When anaerobically purified, the isolated soluble protein contains 3-3.5 iron and 3-3.5 sulfide/polypeptide chain. Mössbauer spectra of the 57Fe-protein revealed that the majority of the iron is in the form of a (4Fe-4S)2+ cluster. An enzymatic assay for quinolinate synthetase activity was set up and allowed to demonstrate that the cluster is absolutely required for NadA activity. Exposure to air leads to degradation of the cluster and inactivate enzyme. << Less
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Crystal structure of the NAD biosynthetic enzyme quinolinate synthase.
Sakuraba H., Tsuge H., Yoneda K., Katunuma N., Ohshima T.
A gene encoding a quinolinate synthase has been identified in the hyperthermophilic archaeon Pyrococcus horikoshii via genome sequencing. The gene was overexpressed in Escherichia coli, and the crystal structure of the produced enzyme was determined to 2.0 A resolution in the presence of malate, a ... >> More
A gene encoding a quinolinate synthase has been identified in the hyperthermophilic archaeon Pyrococcus horikoshii via genome sequencing. The gene was overexpressed in Escherichia coli, and the crystal structure of the produced enzyme was determined to 2.0 A resolution in the presence of malate, a substrate analogue. The overall structure exhibits a unique triangular architecture composed of a 3-fold repeat of three-layer (alphabetaalpha) sandwich folding. Although some aspects of the fold homologous to the each domain have been observed previously, the overall structure of quinolinate synthase shows no similarity to any known protein structure. The three analogous domains are related to a pseudo-3-fold symmetry. The active site is located at the interface of the three domains and is centered on the pseudo-3-fold axis. The malate molecule is tightly held near the bottom of the active site cavity. The model of the catalytic state during the first condensation step of the quinolinate synthase reaction indicates that the elimination of inorganic phosphate from dihydroxyacetone phosphate may precede the condensation reaction. << Less