5cae

Succinate bound to pig GTP-specific succinyl-CoA synthetase

spinqualitylabelsall models 5cae, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5cae is a 2 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.2Å Ligands: CL, COA, CSS, GOL, MG, PO4, SIN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SUCA_PIG Catalyzes the ATP- or GTP-dependent ligation of succinate and CoA to form succinyl-CoA. The nature of the beta subunit determines the nucleotide specificity (By similarity). Publication Abstract from PubMed Succinyl-CoA synthetase catalyzes the only step in the citric acid cycle that provides substrate-level phosphorylation. Although the binding sites for the substrates CoA, phosphate, and the nucleotides ADP and ATP or GDP and GTP have been identified, the binding site for succinate has not. To determine this binding site, pig GTP-specific succinyl-CoA synthetase was crystallized in the presence of succinate, magnesium ions and CoA, and the structure of the complex was determined by X-ray crystallography to 2.2 A resolution. Succinate binds in the carboxy-terminal domain of the beta-subunit. The succinate-binding site is near both the active-site histidine residue that is phosphorylated in the reaction and the free thiol of CoA. The carboxy-terminal domain rearranges when succinate binds, burying this active site. However, succinate is not in position for transfer of the phosphoryl group from phosphohistidine. Here, it is proposed that when the active-site histidine residue has been phosphorylated by GTP, the phosphohistidine displaces phosphate and triggers the movement of the carboxylate of succinate into position to be phosphorylated. The structure shows why succinyl-CoA synthetase is specific for succinate and does not react appreciably with citrate nor with the other C4-dicarboxylic acids of the citric acid cycle, fumarate and oxaloacetate, but shows some activity with L-malate. Structural basis for the binding of succinate to succinyl-CoA synthetase.,Huang J, Fraser ME Acta Crystallogr D Struct Biol. 2016 Aug;72(Pt 8):912-21. doi:, 10.1107/S2059798316010044. Epub 2016 Jul 13. PMID:27487822 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Succinyl-CoA synthetase 3D structures

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