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bioRxiv · 10.1101/2021.01.15.426676

High-resolution model of Arabidopsis Photosystem II reveals the structural consequences of digitonin-extraction

Graca, A. T.·Hall, M.·Persson, K.·Schröder, W. P.
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Abstract

In higher plants, the photosynthetic process is performed and regulated by Photosystem II (PSII). Arabidopsis thaliana was the first higher plant with a fully sequenced genome, conferring it the status of a model organism; nonetheless, a high-resolution structure of its Photosystem II is missing. We present the first Cryo-EM high-resolution structure of Arabidopsis PSII supercomplex with average resolution of 2.79 [A], an important model for future PSII studies. The digitonin extracted PSII complexes demonstrate the importance of: the LHG2630-lipid-headgroup in the trimerization of the light-harvesting complex II; the stabilization of the PsbJ subunit and the CP43-loop E by DGD520-lipid; the choice of detergent for the integrity of membrane protein complexes. Furthermore, our data shows at the anticipated Mn4CaO5-site a single metal ion density as a reminiscent early stage of Photosystem II photoactivation.

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Graca, A. T., Hall, M., Persson, K., Schröder, W. P.. 2021-01-17. High-resolution model of Arabidopsis Photosystem II reveals the structural consequences of digitonin-extraction. https://doi.org/10.1101/2021.01.15.426676

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