English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Crystal and NMR structures are essential and fundamental in performing almost all molecular modelling techniques. Three dimensions resolution of such structures is certainly one of the most crucial criteria of quality and credibility. Researchers made great effort to prepare crystals of photosystem II (PS II) from algae and higher plants in the last decades. However, till now there are only two experimental crystal structures resolved at adequate resolution. Both are from the same common organism Thermosynechococcus elongatus. First was obtained at 3.5 Å (PDB code: 1S5L) [1] and second at 3.2 Å (PDB code: 1W5C) [2] overall resolution. By performing series of molecular dynamics (MD) simulations at appropriate time scales also coupled partially with quantum-chemical calculations, it is possible to increase the model accuracy mainly in the regions, where the probability of spatial orientation of amino acid side chain lacks appropriate electron density or other sources of experimental data. We present here more natural-like, geometrically optimised structures of extended reaction centre (RC) of PS II. Recently, changes in excitonic interactions of PS II RC pigments upon light-induced oxidation of primary donor (P680) or reduction of primary acceptor pheophytin a (Phe a), were analysed using absorption and circular dichroism (CD) spectra [3, 4]. In contrast to the oxidation of primary donor, the lightinduced change in the CD spectrum upon primary acceptor reduction was temperature-dependent. This suggests a hypothesis that at a room temperature the reduced Phe a induces conformational changes of the RC protein environment, which affects the excitonic interaction of the RC chlorophylls. Having optimised structural models of PS II RC we were able to elucidate and describe some of the details of these processes.

Refined structural model of photosystem II fromThermosynechococcus elongatus, structural changes in reaction centre