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Photobleaching Enables Super-resolution Imaging of the FtsZ Ring in the Cyanobacterium Prochlorococcus
Published on: November 6, 2018
Antenna ring around trimeric Photosystem I in chlorophyll b containing cyanobacterium Prochlorothrix hollandica
Ladislav Bumba1, Ondrej Prasil, Frantisek Vacha
1Institute of Plant Molecular Biology, Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic. bumba@seznam.cz
Abstract:
Prochlorothrix hollandica is one of the three known species of an unusual clade of cyanobacteria (formerly called "prochlorophytes") that contain chlorophyll a and b molecules bound to intrinsic light-harvesting antenna proteins. Here, we report the structural characterization of supramolecular complex consisting of Photosystem I (PSI) associated with the chlorophyll a/b-binding Pcb proteins. Electron microscopy and single particle image analysis of negatively stained preparations revealed that the Pcb-PSI supercomplex consists of a central trimeric PSI surrounded by a ring of 18 Pcb subunits. We conclude that the formation of the Pcb ring around trimeric PSI represents a mechanism for increasing the light-harvesting efficiency in chlorophyll b-containing cyanobacteria.
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