title: The structure of bovine F1-ATPase in complex with its regulatory protein IF1.
abstract: In mitochondria, the hydrolytic activity of ATP synthase is prevented by an inhibitor protein, IF1. The active bovine protein (84 amino acids) is an alpha-helical dimer with monomers associated via an antiparallel alpha-helical coiled coil composed of residues 49-81. The N-terminal inhibitory sequences in the active dimer bind to two F1-ATPases in the presence of ATP. In the crystal structure of the F1-IF1 complex at 2.8 A resolution, residues 1-37 of IF1 bind in the alpha(DP)-beta(DP) interface of F1-ATPase, and also contact the central gamma subunit. The inhibitor opens the catalytic interface between the alpha(DP) and beta(DP) subunits relative to previous structures. The presence of ATP in the catalytic site of the beta(DP) subunit implies that the inhibited state represents a pre-hydrolysis step on the catalytic pathway of the enzyme.
authors.affiliation: The Medical Research Council Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, UK.
authors.forename: Elena
authors.initials: E
authors.lastname: Cabezón
authors.forename: Martin G
authors.initials: MG
authors.lastname: Montgomery
authors.forename: Andrew G W
authors.initials: AG
authors.lastname: Leslie
authors.forename: John E
authors.initials: JE
authors.lastname: Walker
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D002417:Cattle; D018360:Crystallography, X-Ray; D019281:Dimerization; D006868:Hydrolysis; D008928:Mitochondria / Q000378:metabolism; D008958:Models, Molecular; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D000097795:ATPase Inhibitory Protein
chemical_list: D000255:Adenosine Triphosphate; D011506:Proteins; D006180:Proton-Translocating ATPases; D000097795:ATPase Inhibitory Protein