title: Conformational changes in the Escherichia coli ATP synthase b-dimer upon binding to F(1)-ATPase.
abstract: Conformational changes within the subunit b-dimer of the E. coli ATP synthase occur upon binding to the F(1) sector. ESR spectra of spin-labeled b at room temperature indicated a pivotal point in the b-structure at residue 62. Spectra of frozen b +/- F(1) and calculated interspin distances suggested that where contact between b (2) and F(1) occurs (above about residue 80), the structure of the dimer changes minimally. Between b-residues 33 and 64 inter-subunit distances in the F(1)-bound b-dimer were found to be too large to accommodate tightly coiled coil packing and therefore suggest a dissociation and disengagement of the dimer upon F(1)-binding. Mechanistic implications of this "bubble" formation in the tether domain of ATP synthase b ( 2 ) are discussed.
authors.affiliation: Department of Biological Sciences, Southern Methodist University, 6501 Airline Rd., Dallas, TX 75275, USA.
authors.forename: Tarek M
authors.initials: TM
authors.lastname: Zaida
authors.forename: Tassilo
authors.initials: T
authors.lastname: Hornung
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Volkov
authors.forename: Andrea D
authors.initials: AD
authors.lastname: Hoffman
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Pandey
authors.forename: John G
authors.initials: JG
authors.lastname: Wise
authors.forename: Pia D
authors.initials: PD
authors.lastname: Vogel
mesh_terms: D025181:ATP Synthetase Complexes / Q000737:chemistry* / Q000648:ultrastructure*; D001665:Binding Sites; D003198:Computer Simulation; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology*; D008956:Models, Chemical; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000648:ultrastructure; D011485:Protein Binding; D011487:Protein Conformation; D021122:Protein Subunits; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D046912:Multiprotein Complexes; D021122:Protein Subunits; D025181:ATP Synthetase Complexes; D006180:Proton-Translocating ATPases