plastokyanin
Plastocyanin, occasionally spelled plastokyanin, is a small copper-containing protein that plays a key role in photosynthetic electron transport. It is found in the thylakoid lumen of chloroplasts in green plants and algae and in cyanobacteria, serving as a mobile electron carrier between the cytochrome b6f complex and photosystem I. In plants, plastocyanin is one of several copper-containing electron carriers that participate in linear electron flow from water splitting to NADP+ reduction.
Chemically, plastocyanin is a type 1 blue copper protein of about 8–10 kDa. Its active site contains
Functionally, plastocyanin accepts an electron from cytochrome f and passes it to the P700 chlorophyll pair
Genetic and evolutionary notes: plastocyanin is part of the cupredoxin family. The PETE gene encodes plastocyanin