Subproject 4

Biogenesis of thylakoid membranes in cyanobacteria

Project leader: Prof. Dr. Jörg Nickelsen

Thylakoid membranes harbour the components mediating the photosynthetic electron transport including photosystem II (PSII) which catalyzes light-driven charge separation and water oxidation. Recent work on cyanobacterial PSII has shown that its assembly proceeds in a highly-ordered, step-wise manner and is initiated at specialized membranous structures close to the plasma membrane, named biogenesis centers. These centers are characterized by the accumulation of the PratA factor, a protein that preloads early PSII intermediates with manganese ions which subsequently form the oxygen-evolving apparatus of PSII. In this project, we aim at using PratA and its recently identified interaction partners as molecular entry points for the elucidation of (i) the manganese delivery process to PSII and (ii) its evolutionary development. (iii) Moreover, this project focusses on the function and ultrastructure of cyanobacterial biogenesis centers and the role that the SynCURT1 factor plays during their formation.