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

Chen, Min; Floetenmeyer, Matthias; Bibby, Thomas S.

doi:10.1016/j.febslet.2009.07.012

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Volume 583, Issue 15 , Pages 2535-2539, 6 August 2009

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

Edited by Richard Cogdell

Min Chen
- School of Biological Sciences, University of Sydney, New South Wales 2006, Australia
- Corresponding authors. Address: School of Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH, UK (T.S. Bibby). Fax: +61 2 9351 4119 (M. Chen), +44 2380 596 400 (T.S. Bibby).
Matthias Floetenmeyer
- Centre for Microscopy & Microanalysis, The University of Queensland, Queensland 4072, Australia
Thomas S. Bibby
- School of Biological Sciences, University of Sydney, New South Wales 2006, Australia
- School of Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
- Corresponding authors. Address: School of Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH, UK (T.S. Bibby). Fax: +61 2 9351 4119 (M. Chen), +44 2380 596 400 (T.S. Bibby).

Received 24 May 2009; received in revised form 2 July 2009; accepted 2 July 2009. published online 13 July 2009.

Abstract

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.

Abbreviations: CBPs, accessory chlorophyll-binding-proteins, Chl, chlorophyll, PBP, phycobiliprotein, PS, photosystem, PBS, phycobilisome, PC, phycocyanin, APC, allophycocyanin, TEM, transmission electron microscopy, CEMOVIS, cryo-electron microscopy of vitreous sections, TM, thylakoid membranes