This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2fpi
From Proteopedia
| |||||||
| , resolution 2.700Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | SUCLG1 (Sus scrofa), SUCLG2 (Sus scrofa) | ||||||
| Activity: | Succinate--CoA ligase (GDP-forming), with EC number 6.2.1.4 | ||||||
| Related: | 1EUC, 1EUD, 2FP4, 2FPG, 2FPP
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of pig GTP-specific succinyl-CoA synthetase from polyethylene glycol
Overview
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.
About this Structure
2FPI is a Protein complex structure of sequences from Sus scrofa. Full crystallographic information is available from OCA.
Reference
Interactions of GTP with the ATP-grasp domain of GTP-specific succinyl-CoA synthetase., Fraser ME, Hayakawa K, Hume MS, Ryan DG, Brownie ER, J Biol Chem. 2006 Apr 21;281(16):11058-65. Epub 2006 Feb 15. PMID:16481318
Page seeded by OCA on Mon Mar 31 03:05:59 2008
