InterPro domain: IPR016370

This group represents the photosystem I subunits PsaG and PsaK from plants.

Photosystem I (PSI) [ 1 ] is an integral membrane protein complex that uses light energy to mediate electron transfer from plastocyanin to ferredoxin. It is found in the chloroplasts of plants and cyanobacteria. PSI is composed of at least 14 different subunits, two of which, PSI-G (gene psaG) and PSI-K (gene psaK), are small hydrophobic proteins of about 7 to 9 Kd and evolutionary related [ 2 ]. Both seem to contain two transmembrane regions. Cyanobacteria contain only PSI-K.

1. Structure, function and organization of the Photosystem I reaction center complex. Biochim. Biophys. Acta 895, 167-204
2. The PSI-K subunit of photosystem I from barley (Hordeum vulgare L.). Evidence for a gene duplication of an ancestral PSI-G/K gene. J. Biol. Chem. 268, 18912-6