Photosystem I

Photosystem I (PS I) (or plastocyanin: ferredoxin oxidoreductase) is the second photosystem in the photosynthetic light reactions of algae, plants, and some bacteria. Photosystem I is so named because it was discovered before photosystem II. Aspects of PS I were discovered in the 1950s, but the significances of these discoveries was not yet known. Louis Duysens first proposed the concepts of photosystems I and II in 1960, and, in the same year, a proposal by Fay Bendall and Robert Hill assembled earlier discoveries into a cohesive theory of serial photosynthetic reactions. Hill and Bendall’s hypothesis was later justified in experiments conducted in 1961 by Duysens and Witt groups.

PsaA_PsaB
crystal structure of photosystem i: a photosynthetic reaction center and core antenna system from cyanobacteria
Identifiers
Symbol PsaA_PsaB
Pfam PF00223
InterPro IPR001280
PROSITE PDOC00347
SCOP 1jb0
SUPERFAMILY 1jb0
TCDB 5.B.4
OPM superfamily 2
OPM protein 1jb0
Available protein structures:
Pfam structures
PDB RCSB PDB; PDBe
PDBsum structure summary

Read more about Photosystem I:  Components and Action of Photosystem I, Ycf4 Protein Domain, Green Sulfur Bacteria and The Evolution of PS I