Enzymes
| UniProtKB help_outline | 4,857 proteins |
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- Name help_outline 5-enolpyruvoyl-6-hydroxy-2-succinyl-cyclohex-3-ene-1-carboxylate Identifier CHEBI:58818 (Beilstein: 11278469) help_outline Charge -3 Formula C14H13O9 InChIKeyhelp_outline XYCATPIYKOARSZ-OAIFWDMCSA-K SMILEShelp_outline O[C@@H]1[C@@H](OC(=C)C([O-])=O)C=C[C@@H]([C@H]1C([O-])=O)C(=O)CCC([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 (1R,6R)-6-hydroxy-2-succinyl-cyclohexa-2,4-diene-1-carboxylate Identifier CHEBI:58689 Charge -2 Formula C11H10O6 InChIKeyhelp_outline QJYRAJSESKVEAE-PSASIEDQSA-L SMILEShelp_outline O[C@@H]1C=CC=C([C@H]1C([O-])=O)C(=O)CCC([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 pyruvate Identifier CHEBI:15361 (CAS: 57-60-3) help_outline Charge -1 Formula C3H3O3 InChIKeyhelp_outline LCTONWCANYUPML-UHFFFAOYSA-M SMILEShelp_outline CC(=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 219 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:25597 | RHEA:25598 | RHEA:25599 | RHEA:25600 | |
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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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Identification and characterization of (1R,6R)-2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase in the menaquinone Biosynthesis of Escherichia coli.
Jiang M., Chen X., Guo Z.-F., Cao Y., Chen M., Guo Z.
Menaquinone is a lipid-soluble molecule that plays an essential role as an electron carrier in the respiratory chain of many bacteria. We have previously shown that its biosynthesis in Escherichia coli involves a new intermediate, 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate (SEP ... >> More
Menaquinone is a lipid-soluble molecule that plays an essential role as an electron carrier in the respiratory chain of many bacteria. We have previously shown that its biosynthesis in Escherichia coli involves a new intermediate, 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate (SEPHCHC), and requires an additional enzyme to convert this intermediate into (1 R,6 R)-2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC). Here, we report the identification and characterization of MenH (or YfbB), an enzyme previously proposed to catalyze a late step in menaquinone biosynthesis, as the SHCHC synthase. The synthase catalyzes a proton abstraction reaction that results in 2,5-elimination of pyruvate from SEPHCHC and the formation of SHCHC. It is an efficient enzyme ( k cat/ K M = 2.0 x 10 (7) M (-1) s (-1)) that provides a smaller transition-state stabilization than other enzymes catalyzing proton abstraction from carbon acids. Despite its lack of the proposed thioesterase activity, the SHCHC synthase is homologous to the well-characterized C-C bond hydrolase MhpC. The crystallographic structure of the Vibrio cholerae MenH protein closely resembles that of MhpC and contains a Ser-His-Asp triad typical of serine proteases. Interestingly, this triad is conserved in all MenH proteins and is essential for the SHCHC synthase activity. Mutational analysis found that the catalytic efficiency of the E. coli protein is reduced by 1.4 x 10 (3), 2.1 x 10 (5), and 9.3 x 10 (3) folds when alanine replaces serine, histidine, and aspartate of the triad, respectively. These results show that the SHCHC synthase is closely related to alpha/beta hydrolases but catalyzes a reaction mechanistically distinct from all known hydrolase reactions. << Less