This family consists of cytochrome B6-F complex subunit 5 (PetG). The cytochrome bf complex found in green plants, eukaryotic algae and cyanobacteria, connects photosystem I to photosystem II in the electron transport chain, functioning as a plastoquinol:plastocyanin/cytochrome c6 oxidoreductase [1]. PetG or subunit 5 is associated with the bf complex and the absence of PetG affects either the assembly or stability of the cytochrome bf complex in Chlamydomonas reinhardtii [1].

1: The deletion of petG in Chlamydomonas reinhardtii disrupts the cytochrome bf complex. Berthold DA, Schmidt CL, Malkin R; J Biol Chem 1995;270:29293-29298. PMID:7493961

2: Purification and characterization of the cytochrome b6 f complex from Chlamydomonas reinhardtii. Pierre Y, Breyton C, Kramer D, Popot JL; J Biol Chem 1995;270:29342-29349. PMID:7493968