Molecular mechanisms of the redox regulation of translation and the response of photosynthesis to environmental changes

在蓝藻聚胞藻中，伸长因子G是翻译伸长的关键蛋白，在氧化条件下通过在两个特定的半胱氨酸残基之间形成分子内二硫键而失活。PCC 6803。硫氧还蛋白还原二硫键导致EF-G重新激活，提示翻译可能受光合作用电子传递所产生的还原功率的调节。在集合体细胞中，丝氨酸取代EF-G的目标半胱氨酸残基可以保护光系统II免受光抑制。

Elongation factor G, a key protein in translation elongation, was inactivated via the formation of an intramolecular disulfide bond between two specific cysteine residues under oxidative conditions in the cyanobacterium Synechocystissp. PCC 6803. Reduction of the disulfide bond by thioredoxin resulted in the reactivation of EF-G, suggesting that translation might be regulated by the reducing power derived from the photosynthetic electron transport. Replacement of the target cysteine residue of EF-G by serine in Synechocystiscells protected photosystem II from photoinhibition.