Biological nano motor, ATP synthase FoF1:: from catalysis to γεc10-12 subunit assembly rotation

Proton translocating ATPase (ATP synthase), a chemiosmotic enzyme, synthesizes ATP from ADP and phosphate coupling with the electrochemical ion gradient across the membrane. This enzyme has been studied extensively by combined genetic, biochemical and biophysical approaches. Such studies revealed a unique mechanism which transforms an electrochemical ion gradient into chemical energy through the rotation of a subunit assembly. Thus, this enzyme can be defined as a nano motor capable of coupling a chemical reaction and ion translocation, or more simply, as a protein complex carrying out rotational catalysis. In this article, we briefly discuss our recent work, emphasizing the rotation of subunit assembly (gamma epsilon c(10-12)) which is formed from peripheral and intrinsic membrane subunits. (C) 2000 Elsevier Science B.V. All rights reserved.