The 8 kDa polypeptide in photosystem I is a probable candidate of an iron-sulfur center protein coded by the chloroplast gene frxA

AbstractThe N-terminal sequence of the 8 kDa polypeptide isolated from spinach photosystem I (PS I) particles was determined by a gas-phase sequencer. The sequence showed the characteristic distribution of cysteine residues in the bacterial-type ferredoxins and was highly homologous to that deduced from the chloroplast gene frxA of liverwort, Marchantia polymorpha. It is strongly suggested that the 8 kDa polypeptide has to be an apoprotein of one of the iron-sulfur center proteins in PS I particles