4YW8
Structure of rat cytosolic pepck in complex with 3-mercaptopicolinic acid
Summary for 4YW8
| Entry DOI | 10.2210/pdb4yw8/pdb |
| Descriptor | Phosphoenolpyruvate carboxykinase, cytosolic [GTP], MANGANESE (II) ION, SODIUM ION, ... (8 entities in total) |
| Functional Keywords | kinase, gluconeogenesis, lyase, transferase |
| Biological source | Rattus norvegicus (Rat) |
| Total number of polymer chains | 1 |
| Total formula weight | 70291.29 |
| Authors | Balan, M.D.,Johnson, T.A.,Mcleod, M.J.,Lotosky, W.R.,Holyoak, T. (deposition date: 2015-03-20, release date: 2015-09-23, Last modification date: 2024-12-25) |
| Primary citation | Balan, M.D.,Mcleod, M.J.,Lotosky, W.R.,Ghaly, M.,Holyoak, T. Inhibition and Allosteric Regulation of Monomeric Phosphoenolpyruvate Carboxykinase by 3-Mercaptopicolinic Acid. Biochemistry, 54:5878-5887, 2015 Cited by PubMed Abstract: For almost 40 years, it has been known that tryptophan metabolites and picolinic acid analogues act as inhibitors of gluconeogenesis. Early studies observed that 3-mercaptopicolinic acid (MPA) was a potent hypoglycemic agent via inhibition of glucose synthesis through the specific inhibition of phosphoenolpyruvate carboxykinase (PEPCK) in the gluconeogenesis pathway. Despite prior kinetic investigation, the mechanism of the inhibition by MPA is unclear. To clarify the mechanism of inhibition exerted by MPA on PEPCK, we have undertaken structural and kinetic studies. The kinetic data in concert with crystallographic structures of PEPCK in complex with MPA and the substrates for the reaction illustrate that PEPCK is inhibited by the binding of MPA at two discrete binding sites: one acting in a competitive fashion with PEP/OAA (∼10 μM) and the other acting at a previously unidentified allosteric site (Ki ∼ 150 μM). The structural studies suggest that binding of MPA to the allosteric pocket stabilizes an altered conformation of the nucleotide-binding site that in turn reduces the affinity of the enzyme for the nucleotide. PubMed: 26322521DOI: 10.1021/acs.biochem.5b00822 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.55 Å) |
Structure validation
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