title: The structure of the membrane extrinsic region of bovine ATP synthase.
abstract: The structure of the complex between bovine mitochondrial F(1)-ATPase and a stator subcomplex has been determined at a resolution of 3.2 A. The resolved region of the stator contains residues 122-207 of subunit b; residues 5-25 and 35-57 of F(6); 3 segments of subunit d from residues 30-40, 65-74, and 85-91; and residues 1-146 and 169-189 of the oligomycin sensitivity conferral protein (OSCP). The stator subcomplex represents its membrane distal part, and its structure has been augmented with an earlier structure of a subcomplex containing residues 79-183, 3-123, and 5-70 of subunits b, d, and F(6), respectively, which extends to the surface of the inner membrane of the mitochondrion. The N-terminal domain of the OSCP links the stator with F(1)-ATPase via alpha-helical interactions with the N-terminal region of subunit alpha(E). Its C-terminal domain makes extensive helix-helix interactions with the C-terminal alpha-helix of subunit b from residues 190-207. Subunit b extends as a continuous 160-A long alpha-helix from residue 188 back to residue 79 near to the surface of the inner mitochondrial membrane. This helix appears to be stiffened by other alpha-helices in subunits d and F(6), but the structure can bend inward toward the F(1) domain around residue 146 of subunit b. The linker region between the 2 domains of the OSCP also appears to be flexible, enabling the stator to adjust its shape as it passes over the changing profile of the F(1) domain during a catalytic cycle. The structure of the membrane extrinsic part of bovine ATP synthase is now complete.
authors.affiliation: Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, United Kingdom.
authors.forename: David M
authors.initials: DM
authors.lastname: Rees
authors.forename: Andrew G W
authors.initials: AG
authors.lastname: Leslie
authors.forename: John E
authors.initials: JE
authors.lastname: Walker
mesh_terms: D000818:Animals; D002417:Cattle; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009840:Oligomycins / Q000494:pharmacology; D011487:Protein Conformation
chemical_list: D009840:Oligomycins; C474451:F1F0-ATP synthase; D025261:Mitochondrial Proton-Translocating ATPases