Protection by α-tocopherol of the repair of photosystem II during photoinhibition in Synechocystis sp. PCC 6803.

α-Tocopherol is a lipophilic antioxidant that is an efficient scavenger of singlet oxygen. We investigated the role of α-tocopherol in the protection of photosystem II (PSII) from photoinhibition using a mutant of the cyanobacterium Synechocystis sp. PCC 6803 that is deficient in the biosynthesis of α-tocopherol.

Differences in the interactions between the subunits of photosystem II dependent on D1 protein variants in the thermophilic cyanobacterium Thermosynechococcus elongatus.

The main cofactors involved in the oxygen evolution activity of Photosystem II (PSII) are located in two proteins, D1 (PsbA) and D2 (PsbD). In Thermosynechococcus elongatus, a thermophilic cyanobacterium, the D1 protein is encoded by either the psbA(1) or the psbA(3) gene, the expression of which is dependent on environmental conditions. It has been shown that the energetic properties of the PsbA1-PSII and those of the PsbA3-PSII differ significantly (Sugiura, M.