This family consists of the plant specific oxygen evolving enhancer protein 3 (PsbQ). Photosystem II (PSII)1 is a pigment-protein complex, which consists of at least 25 different protein subunits, at present denoted PsbA-Z according to the genes that encode them. PsbQ plays an important role in the lumenal oxygen-evolving activity of PSII from higher plants and green algae [1].

1: Structural analysis of the PsbQ protein of photosystem II by Fourier transform infrared and circular dichroic spectroscopy and by bioinformatic methods. Balsera M, Arellano JB, Gutierrez JR, Heredia P, Revuelta JL, De Las Rivas J; Biochemistry 2003;42:1000-1007. PMID:12549920