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BOVINE MITOCHONDRIAL F1-ATPASE INHIBITED BY MG2+ADP AND ALUMINIUM FLUORIDE
Structural highlights
FunctionATPA_BOVIN Mitochondrial membrane ATP synthase (F(1)F(0) ATP synthase or Complex V) produces ATP from ADP in the presence of a proton gradient across the membrane which is generated by electron transport complexes of the respiratory chain. F-type ATPases consist of two structural domains, F(1) - containing the extramembraneous catalytic core, and F(0) - containing the membrane proton channel, linked together by a central stalk and a peripheral stalk. During catalysis, ATP synthesis in the catalytic domain of F(1) is coupled via a rotary mechanism of the central stalk subunits to proton translocation. Subunits alpha and beta form the catalytic core in F(1). Rotation of the central stalk against the surrounding alpha(3)beta(3) subunits leads to hydrolysis of ATP in three separate catalytic sites on the beta subunits. Subunit alpha does not bear the catalytic high-affinity ATP-binding sites (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: The globular domain of the membrane-associated F(1)F(o)-ATP synthase complex can be detached intact as a water-soluble fragment known as F(1)-ATPase. It consists of five different subunits, alpha, beta, gamma, delta and epsilon, assembled with the stoichiometry 3:3:1:1:1. In the crystal structure of bovine F(1)-ATPase determined previously at 2.8 A resolution, the three catalytic beta subunits and the three noncatalytic alpha subunits are arranged alternately around a central alpha-helical coiled coil in the gamma subunit. In the crystals, the catalytic sites have different nucleotide occupancies. One contains the triphosphate form of the nucleotide, the second contains the diphosphate, and the third is unoccupied. Fluoroaluminate complexes have been shown to mimic the transition state in several ATP and GTP hydrolases. In order to understand more about its catalytic mechanism, F(1)-ATPase was inhibited with Mg(2+)ADP and aluminium fluoride and the structure of the inhibited complex was determined by X-ray crystallography. RESULTS: The structure of bovine F(1)-ATPase inhibited with Mg(2+)ADP and aluminium fluoride determined at 2.5 A resolution differs little from the original structure with bound AMP-PNP and ADP. The nucleotide occupancies of the alpha and beta subunits are unchanged except that both aluminium trifluoride and Mg(2+)ADP are bound in the nucleotide-binding site of the beta(DP) subunit. The presence of aluminium fluoride is accompanied by only minor adjustments in the surrounding protein. CONCLUSIONS: The structure appears to mimic a possible transition state. The coordination of the aluminofluoride group has many features in common with other aluminofluoride-NTP hydrolase complexes. Apparently, once nucleotide is bound to the catalytic beta subunit, no additional major structural changes are required for catalysis to occur. Structure of bovine mitochondrial F(1)-ATPase inhibited by Mg(2+) ADP and aluminium fluoride.,Braig K, Menz RI, Montgomery MG, Leslie AG, Walker JE Structure. 2000 Jun 15;8(6):567-73. PMID:10873854[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
