Reconstitution of Cyclic Electron Transport in Synechocystis sp. PCC 6803 by a Cell-Free System


Cyanobacteria possess a high activity of cyclic electron transport (CET). However, the components are still not identified completely. To elucidate the possible component(s), we have reconstitute the CET in vitro in Synechocystis sp. PCC 6803 (Synechocystis 6803) by isolated thylakoid membranes (thylakoids) and soluble fractions, by monitoring the rereduction kinetics of P700+. The P700+ was rereduced with a significant rate by addition of a soluble fraction. Either NADPH or NADH accelerated the reduction. The results indicate that a soluble component(s) is/are prerequisite for reconstitution.

Photosynthesis. Energy from the Sun