Conformational changes in the Escherichia coli ATP synthase b-dimer upon binding to F(1)-ATPase.
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.
Zaida
Tarek M
TM
Department of Biological Sciences, Southern Methodist University, 6501 Airline Rd., Dallas, TX 75275, USA.
Hornung
Tassilo
T
Volkov
Oleg A
OA
Hoffman
Andrea D
AD
Pandey
Susan J
SJ
Wise
John G
JG
Vogel
Pia D
PD
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
D046912:Multiprotein Complexes; D021122:Protein Subunits; D025181:ATP Synthetase Complexes; D006180:Proton-Translocating ATPases