The structure of bovine F1-ATPase inhibited by ADP and beryllium fluoride

The structure of bovine F-1-ATPase inhibited with ADP and beryllium fluoride at 2.0Angstrom resolution contains two ADP.BeF3- complexes mimicking ATP, bound in the catalytic sites of the beta(TP) and beta(DP) subunits. Except for a 1Angstrom shift in the guanidinium of alphaArg373, the conformations of catalytic side chains are very similar in both sites. However, the ordered water molecule that carries out nucleophilic attack on the gamma-phosphate of ATP during hydrolysis is 2.6Angstrom from the beryllium in the beta(DP) subunit and 3.8Angstrom away in the beta(TP) subunit, strongly indicating that the beta(DP) subunit is the catalytically active conformation. In the structure of F-1-ATPase with five bound ADP molecules ( three in alpha-subunits, one each in the beta(TP) and beta(DP) subunits), which has also been determined, the conformation of alphaArg373 suggests that it senses the presence ( or absence) of the gamma-phosphate of ATP. Two catalytic schemes are discussed concerning the various structures of bovine F-1-ATPase.