Plant Biology Seminar

Biogenesis of Cyanobacterial Thylakoid Membranes

Cyanobacteria, algae and plants convert light energy into chemical energy by using a very similar type of photosynthetic membrane system, named thylakoids. Current molecular analyses suggest that the biogenesis of the cyanobacterial energy conversion system, in particular photosystem (PS) II, is initiated in dedicated membrane sub-fractions at the cellular periphery. Here, these membranes form centres which are marked by the manganese- transporting PS II assembly factor PratA. PratA forms a complex with the protease HhoA and a pilus-related factor. Moreover, center formation depends on the membrane curving protein CurT, a homolog of the chloroplast grana-forming CURT1 protein family. By applying cryo EM tomography, we dismantled the in situ ultrastructure of biogenesis centers.