Anti-oxidative stress system in cyanobacteria Synechocystis sp. PCC6803

Abstract

SLL1621, annotated as AhpC/TSA family protein in CyanoBase, is a target candidate protein of thioredoxin in the cyanobacteria Synechocystis sp. PCC 6803. Based on sequence homology analysis SLL1621 is categorized into type II peroxiredoxin. The disruptant of the sll1621 gene was hard to survive even under weak light conditions (50 μmol m^-2 s^-1), suggesting the physiological significance of this protein. In vitro interaction between SLL1621 and thioredoxin was confirmed using the recombinant proteins expressed in Escherichia coli. However we found that SLL1621 shows remarkable glutathione dependent peroxidase activity. The role of SLL1621 protein in the cell will be discussed.