CHLOROPLAST F_1-ATPASE: MOLECULAR MECHANISM OF THE PHYTOTOXIN TENTOXIN

摘要

F_0F_1 ATP synthases located in the energy transducing membranes of bacteria, mitochondria and chloroplasts catalyse ATP synthesis and ATP hydrolysis coupled with transmembrane proton transport. The FoFpholoenzymes consist of an extra-membranous catalytic F_1 domain containing five different polypeptides in a stoichiometry of alpha_3beta_3gamma delta epsilon and a membrane intrinsic F_0 domain, composed of subunits a, b and c which mediate proton transfer across the membrane. Structure and molecularmechanism of the membrane extrinsic F_1 domain have been solved with the mitochondrial, bacterial and chloroplast enzymes (Abrahams et al 1994, Bianchet et al 1998, Stock et al 1999, Shirakihara et al 1997, Groth & Pohl 2001). But a detailed structure ofthe membrane embedded F_0 domain which is expected to provide molecular details on the mechanism of proton transfer and energy coupling is still unknown.