The chloroplast ATP synthase belongs to the family of F1-type ATPases, which are also present in bacteria and mitochondria. ATP synthase generates ATP from ADP and inorganic phosphate using energy derived from a trans-thylakoidal electrochemical proton gradient. CF 0 ß subunit is a catalytic peripheral subunit of ATP synthase stator part which binds nucleotides and forms hexameric ring with CF 0 a subunit.