Abstract
Elongation factor G (EF-G), a key protein in translational elongation, is sensitive to oxidative stress. We have recently found that EF-G is inactivated upon oxidation of two specific Cys residues and subsequent formation of an intramolecular disulfide bond in the cyanobacterium Synechocystis sp. PCC 6803. In the present study, we examined the role of EF-G (Slr1463) in the synthesis of proteins under strong light that causes oxidative stress. In a mutant that overexpresses EF-G, the synthesis of the D1 protein de novo is enhanced under strong light, whereas the synthesis of most of other proteins de novo was repressed. In this mutant, the level of another EF-G homolog Sll1098 was decreased. These observations suggest that EF-G (Slr1463) might be specific to the light-dependent synthesis of proteins.
