Pigment-protein complexes are organized into stable microdomains in cyanobacterial thylakoids

Publication date: Available online 22 July 2019Source: Biochimica et Biophysica Acta (BBA) - BioenergeticsAuthor(s): A. Strašková, G. Steinbach, G. Konert, E. Kotabová, J. Komenda, M. Tichý, R. KaňaAbstractThylakoids are the place of the light-photosynthetic reactions. To gain maximal efficiency, these reactions are conditional to proper pigment-pigment and protein-protein interactions. In higher plants thylakoids, the interactions lead to a lateral asymmetry in localization of protein complexes (i.e. granal/stromal thylakoids) that have been defined as a domain-like structures characteristic by different biochemical composition and function (Albertsson P-Å. 2001,Trends Plant Science 6: 349–354). We explored this complex organization of thylakoid pigment-proteins at single cell level in the cyanobacterium Synechocystis sp. PCC 6803. Our 3D confocal images captured heterogeneous distribution of all main photosynthetic pigment-protein complexes (PPCs), Photosystem I (fluorescently tagged by YFP), Photosystem II and Phycobilisomes. The acquired images depicted cyanobacterial thylakoid membrane as a stable, mosaic-like structure formed by microdomains (MDs). These microcompartments are of sub-micrometer in sizes (~0.5–1.5 μm), typical by particular PPCs ratios and importantly without full segregation of observed complexes. The most prevailing MD is represented by MD with high Photosystem I content which allows also partial separation of Photosystems like in higher pl...

Source: Biochimica et Biophysica Acta (BBA) Bioenergetics - July 23, 2019 Category: Biochemistry Source Type: research