Biochemistry, Department of


Date of this Version



Plant Physiol. (1994) 104: 1459-1461


Copyright American Society of Plant Biologists. Used by permission.


The psaC gene encodes PsaC, the apoprotein for the terminal iron-sulfur clusters, FA and FB, in the PSI reaction center of cyanobacteria, algae, and higher plants. PsaC functions as a membrane-bound oxidoreductase, accepting electrons from the Fx iron-sulfur cluster located on the PsaA/PsaB heterodimer and donating them to the soluble electron transfer proteins Fd and flavodoxin (reviewed in Bryant, 1992). The objective of our work is to clarify the role of PsaC in linear and cyclic electron transfer. The experimental organism is Syneckococcus sp. PCC 6301, a unicellular, freshwater cyanobacterium that is used extensively for physiological, biochemical, and spectroscopic studies of photosynthesis. The PSI complex of Syneckococcus sp. PCC 6301 is widely used in structural and functional studies of the FA and FB ironsulfur clusters (Parrett et al., 1990).