2FPG

Crystal structure of pig GTP-specific succinyl-CoA synthetase in complex with GDP

Summary for 2FPG

• Entry DOI: 10.2210/pdb2fpg/pdb
• Related: 1EUC 1EUD 2FP4 2FPI 2FPP
• Descriptor: Succinyl-CoA ligase [GDP-forming] alpha-chain, mitochondrial, Succinyl-CoA ligase [GDP-forming] beta-chain, mitochondrial, PHOSPHATE ION, ... (6 entities in total)
• Functional Keywords: active site histidine residue, ligase
• Biological source: Sus scrofa (pig); More
• Cellular location: Mitochondrion : P53590
• Total number of polymer chains: 2
• Total formula weight: 75302.88

Authors

Fraser, M.E. (deposition date: 2006-01-16, release date: 2006-02-21, Last modification date: 2024-02-14)

Primary citation

Fraser, M.E.,Hayakawa, K.,Hume, M.S.,Ryan, D.G.,Brownie, E.R.
Interactions of GTP with the ATP-grasp Domain of GTP-specific Succinyl-CoA Synthetase
J.Biol.Chem., 281:11058-11065, 2006

PubMed Abstract: Two isoforms of succinyl-CoA synthetase exist in mammals, one specific for ATP and the other for GTP. The GTP-specific form of pig succinyl-CoA synthetase has been crystallized in the presence of GTP and the structure determined to 2.1 A resolution. GTP is bound in the ATP-grasp domain, where interactions of the guanine base with a glutamine residue (Gln-20beta) and with backbone atoms provide the specificity. The gamma-phosphate interacts with the side chain of an arginine residue (Arg-54beta) and with backbone amide nitrogen atoms, leading to tight interactions between the gamma-phosphate and the protein. This contrasts with the structures of ATP bound to other members of the family of ATP-grasp proteins where the gamma-phosphate is exposed, free to react with the other substrate. To test if GDP would interact with GTP-specific succinyl-CoA synthetase in the same way that ADP interacts with other members of the family of ATP-grasp proteins, the structure of GDP bound to GTP-specific succinyl-CoA synthetase was also determined. A comparison of the conformations of GTP and GDP shows that the bases adopt the same position but that changes in conformation of the ribose moieties and the alpha- and beta-phosphates allow the gamma-phosphate to interact with the arginine residue and amide nitrogen atoms in GTP, while the beta-phosphate interacts with these residues in GDP. The complex of GTP with succinyl-CoA synthetase shows that the enzyme is able to protect GTP from hydrolysis when the active-site histidine residue is not in position to be phosphorylated.

PubMed: 16481318
DOI: 10.1074/jbc.M511785200

Experimental method

X-RAY DIFFRACTION (2.96 Å)