The ε subunit of bacterial and chloroplast F1F0 ATPases -: Structure, arrangement, and role of the ε subunit in energy coupling within the complex

Recent studies show that the epsilon subunit of bacterial and chloroplast F1F0 ATPases is a component of the central stalk that links the F-1 and F-0 parts. This subunit interacts with alpha, beta and gamma subunits of F-1 and the c subunit ring of F-0. Along with the gamma subunit, epsilon is a part of the rotor that couples events at the three catalytic sites sequentially with proton translocation through the F-0 part. Structural data on the epsilon subunit when separated from the complex and in situ are reviewed, and the functioning of this polypeptide in coupling within the ATP synthase is considered. (C) 2000 Elsevier Science B.V. All rights reserved.