Role of minor subunits in the structural asymmetry of the Escherichia coli F1-ATPase.

The beta subunits of the Escherichia coli F1-ATPase react independently with chemical reagents (Stan-Lotter, H. and Bragg, P.D. (1986) Arch. Biochem. Biophys. 248, 116-120). Thus, one beta subunit is readily crosslinked to the epsilon subunit, another reacts with N-N'-dicyclohexylcarbodiimide (DCCD), and a third one is modified by 4-chloro-7-nitrobenzofurazan (NbfCl). This asymmetric behaviour is not due to the association of the delta and epsilon subunits of the ATPase molecule with specific beta subunits since it is maintained in a delta, epsilon-deficient form of the enzyme.