Structure of a PSI-LHCI-cyt b₆f supercomplex in Chlamydomonas reinhardtii promoting cyclic electron flow under anaerobic conditions.

ABSTRACT: Photosynthetic linear electron flow (LEF) produces ATP and NADPH, while cyclic electron flow (CEF) exclusively drives photophosphorylation to supply extra ATP. The fine-tuning of linear and cyclic electron transport levels allows photosynthetic organisms to balance light energy absorption with cellular energy requirements under constantly changing light conditions. As LEF and CEF share many electron transfer components, a key question is how the same individual structural units contribute to these two different functional modes. Here, we report the structural identification of a photosystem I (PSI)-light harvesting complex I (LHCI)-cytochrome (cyt) b₆f supercomplex isolated from the unicellular alga Chlamydomonas reinhardtii under anaerobic conditions, which induces CEF.

SUBMITTER: Steinbeck J 

PROVIDER: S-EPMC6187136 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature