Structure of a large photosystem II supercomplex from Acaryochloris marina.
Acaryochloris marina is a prochlorophyte-like cyanobacterium containing both phycobilins and chlorophyll d as light harvesting pigments. We show that the chlorophyll d light harvesting system, composed of Pcb proteins, functionally associates with the photosystem II (PSII) reaction center (RC) core to form a giant supercomplex. This supercomplex has a molecular mass of about 2300 kDa and dimensions of 385 A x 240 A. It is composed of two PSII-RC core dimers arranged end-to-end, flanked by eight symmetrically related Pcb proteins on each side. Thus each PSII-RC monomer has four Pcb subunits acting as a light harvesting system which increases the absorption cross section of the PSII-RC core by almost 200%.
Chen
Min
M
School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia.
Bibby
Thomas S
TS
Nield
Jon
J
Larkum
Anthony W D
AW
Barber
James
J
D000458:Cyanobacteria / Q000737:chemistry* / Q000648:ultrastructure; D008854:Microscopy, Electron; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000648:ultrastructure*; D013057:Spectrum Analysis; D020524:Thylakoids / Q000737:chemistry
D045332:Photosystem II Protein Complex