The phosphorylation of ADP involves three specific subunits within the CF1 domain:
α subunit: This subunit contains the active site for ATP synthesis and hydrolysis. It binds ADP and inorganic phosphate (Pi) and facilitates the chemical reaction that converts ADP to ATP.
β subunit: The β subunit assists in the binding of ADP and Pi to the catalytic site on the α subunit. It also participates in the conformational changes that occur during ATP synthesis and hydrolysis.
γ subunit: The γ subunit plays a crucial role in energy transduction. It connects the rotating c-subunit in the transmembrane domain (CF0) to the catalytic α- and β-subunits in the CF1 domain. The rotation of the γ subunit due to the proton gradient across the thylakoid membrane drives the conformational changes that lead to ADP phosphorylation.
These three subunits, along with other components of the CF1 domain, work together to facilitate the phosphorylation of ADP and the synthesis of ATP in the chloroplast ATP synthase.
