EFFECT OF DELETIONS FROM THE N-TERMINUS ON THE FUNCTIONS OF THE gamma SUBUNIT OF THE CHLOROPLAST ATP SYNTHASE

摘要

The chloroplast ATP synthase consists of two parts: CF_0 and CF_1. CF_0, a membrane-spanning complex, conducts protons flux through the thylakoid membrane and provides affinity sites for CF_1 complex. CF_1, extrinsic to the membrane, contains the nucleotide-binding and catalytic sites, and can hydrolyze ATP at high rates after appropriate treatment. The CF_1 complex consists of five types of subunits with the stoichiometry of alpha_3beta_3gamma delta epsilon. The catalytic core of the enzyme is alpha_3 beta_3 gamma, despite alpha beta exhibiting lower rates of ATP hydrolysis (Matsui & Yoshida 1995).