Supramolecular organization of phycobiliproteins in the chlorophyll d-containing cyanobacterium Acaryochloris marina

• Published in: FEBS letters Vol. 583; no. 15; pp. 2535 - 2539
• Main Authors: Chen, Min, Floetenmeyer, Matthias, Bibby, Thomas S.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 06-08-2009
• Subjects: Acaryochloris marina; accessory chlorophyll-binding-proteins; allophycocyanin; APC; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; CBPs; CEMOVIS; Chl; chlorophyll; Chlorophyll - chemistry; Chlorophyll - metabolism; Cryo-electron microscopy; cryo-electron microscopy of vitreous sections; Cyanobacteria; Cyanobacteria - chemistry; Cyanobacteria - metabolism; Cyanobacteria - ultrastructure; Freshwater; Membrane organization; Models, Molecular; PBP; PBS; Photosynthesis - physiology; Photosynthetic Reaction Center Complex Proteins - chemistry; Photosynthetic Reaction Center Complex Proteins - metabolism; photosystem; Phycobiliprotein; Phycobiliproteins - chemistry; Phycobiliproteins - metabolism; phycobilisome; phycocyanin; Protein Conformation; TEM; thylakoid membranes; Thylakoids - chemistry; Thylakoids - ultrastructure; transmission electron microscopy; PBS; PS; Acaryochloris marina; Chl; Phycobiliprotein; Cryo-electron microscopy; PC; APC; Membrane organization; TM; CBPs; TEM; CEMOVIS; PBP
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2009.07.012

Here we report the high-resolution detail of the organization of phycobiliprotein structures associated with photosynthetic membranes of the chlorophyll d-containing cyanobacterium Acaryochloris marina. Cryo-electron transmission-microscopy on native cell sections show extensive patches of near-crystalline phycobiliprotein rods that are associated with the stromal side of photosynthetic membranes. This supramolecular photosynthetic structure represents a novel mechanism of organizing the photosynthetic light-harvesting machinery. In addition, the specific location of phycobiliprotein patches suggests a physical separation of photosystem I and photosystem II reaction centres. Based on this finding and the known photosystem’s structure in Acaryochloris, we discuss possible membrane arrangements of photosynthetic membrane complexes in this species.