The effect of depletion of nucleotide and of delta and epsilon subunits on ATP synthesis in dimethyl sulfoxide by F1-ATPase of Escherichia coli.
The F1-ATPase of Escherichia coli contains 3 mol bound adenine nucleotide/mol F1. It is of the F1[2,1] type based on the ability of GTP to displace 1 mol adenine nucleotide/mol F1 (Kironde, F.A.S. and Cross, R.L. (1986) J. Biol. Chem. 261, 12544-12549). A portion of the adenine nucleotide (2 mol/mol F1) is not displaceable by GTP. F1[2,1] was converted to F1[1,0]. This form of the enzyme synthesized ATP from endogenous ADP and inorganic phosphate in a medium containing 30% (v/v) dimethyl sulfoxide (Me2SO). A delta,epsilon subunit-depleted form of the F1-ATPase was shown to be predominantly in the F1[0,1] form. ATP was not synthesized from endogenous ADP by the subunit-depleted enzyme in Me2SO unless additional molecules of ADP were bound. It is concluded that ATP synthesis from endogenous ADP in Me2SO occurs at GTP-nondisplaceable adenine nucleotide binding sites.
Beharry
S
S
Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, Canada.
Bragg
P D
PD
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology*; D006160:Guanosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D046911:Macromolecular Substances; D006180:Proton-Translocating ATPases / Q000378:metabolism*
D046911:Macromolecular Substances; D000244:Adenosine Diphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; D004121:Dimethyl Sulfoxide