2H89

Avian Respiratory Complex II with Malonate Bound

Summary for 2H89

• Entry DOI: 10.2210/pdb2h89/pdb
• Related: 1YQ3 1YQ4 1ZOY 1ZP0 2FBW
• Descriptor: SUCCINATE DEHYDROGENASE FLAVOPROTEIN SUBUNIT, IRON/SULFUR CLUSTER, FE3-S4 CLUSTER, ... (15 entities in total)
• Functional Keywords: complex ii, membrane protein, heme protein, iron sulfur protein, cytochrome b, oxidoreductase, redox enzyme, respiratory chain, malonate, ubiquinone
• Biological source: Gallus gallus (chicken); More
• Total number of polymer chains: 4
• Total formula weight: 127463.72

Authors

Huang, L.S.,Shen, J.T.,Wang, A.C.,Berry, E.A. (deposition date: 2006-06-06, release date: 2006-06-20, Last modification date: 2023-08-30)

Primary citation

Huang, L.S.,Shen, J.T.,Wang, A.C.,Berry, E.A.
Crystallographic studies of the binding of ligands to the dicarboxylate site of Complex II, and the identity of the ligand in the
Biochim.Biophys.Acta, 1757:1073-1083,

PubMed Abstract: Mitochondrial Complex II (succinate:ubiquinone oxidoreductase) is purified in a partially inactivated state, which can be activated by removal of tightly bound oxaloacetate (E.B. Kearney, et al., Biochem. Biophys. Res. Commun. 49 1115-1121). We crystallized Complex II in the presence of oxaloacetate or with the endogenous inhibitor bound. The structure showed a ligand essentially identical to the "malate-like intermediate" found in Shewanella Flavocytochrome c crystallized with fumarate (P. Taylor, et al., Nat. Struct. Biol. 6 1108-1112) Crystallization of Complex II in the presence of excess fumarate also gave the malate-like intermediate or a mixture of that and fumarate at the active site. In order to more conveniently monitor the occupation state of the dicarboxylate site, we are developing a library of UV/Vis spectral effects induced by binding different ligands to the site. Treatment with fumarate results in rapid development of the fumarate difference spectrum and then a very slow conversion into a species spectrally similar to the OAA-liganded complex. Complex II is known to be capable of oxidizing malate to the enol form of oxaloacetate (Y.O. Belikova, et al., Biochim. Biophys. Acta 936 1-9). The observations above suggest it may also be capable of interconverting fumarate and malate. It may be useful for understanding the mechanism and regulation of the enzyme to identify the malate-like intermediate and its pathway of formation from oxaloacetate or fumarate.

PubMed: 16935256
DOI: 10.1016/j.bbabio.2006.06.015

Experimental method

X-RAY DIFFRACTION (2.4 Å)