Structures of a phycobilisome in light-harvesting and photoprotected states

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F22%3A00568506" target="_blank" >RIV/60077344:_____/22:00568506 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60076658:12310/22:43904804

Výsledek na webu

<a href="https://www.nature.com/articles/s41586-022-05156-4" target="_blank" >https://www.nature.com/articles/s41586-022-05156-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s41586-022-05156-4" target="_blank" >10.1038/s41586-022-05156-4</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Structures of a phycobilisome in light-harvesting and photoprotected states

Popis výsledku v původním jazyce

Phycobilisome (PBS) structures are elaborate antennae in cyanobacteria and red algae(1,2). These large protein complexes capture incident sunlight and transfer the energy through a network of embedded pigment molecules called bilins to the photosynthetic reaction centres. However, light harvesting must also be balanced against the risks of photodamage. A known mode of photoprotection is mediated by orange carotenoid protein (OCP), which binds to PBS when light intensities are high to mediate photoprotective, non-photochemical quenching(3-6). Here we use cryogenic electron microscopy to solve four structures of the 6.2 MDa PBS, with and without OCP bound, from the model cyanobacterium Synechocystis sp. PCC 6803. The structures contain a previously undescribed linker protein that binds to the membrane-facing side of PBS. For the unquenched PBS, the structures also reveal three different conformational states of the antenna, two previously unknown. The conformational states result from positional switching of two of the rods and may constitute a new mode of regulation of light harvesting. Only one of the three PBS conformations can bind to OCP, which suggests that not every PBS is equally susceptible to non-photochemical quenching. In the OCP-PBS complex, quenching is achieved through the binding of four 34 kDa OCPs organized as two dimers. The complex reveals the structure of the active form of OCP, in which an approximately 60 angstrom displacement of its regulatory carboxy terminal domain occurs. Finally, by combining our structure with spectroscopic properties(7), we elucidate energy transfer pathways within PBS in both the quenched and light-harvesting states. Collectively, our results provide detailed insights into the biophysical underpinnings of the control of cyanobacterial light harvesting. The data also have implications for bioengineering PBS regulation in natural and artificial light-harvesting systems.

Název v anglickém jazyce

Structures of a phycobilisome in light-harvesting and photoprotected states

Popis výsledku anglicky

Phycobilisome (PBS) structures are elaborate antennae in cyanobacteria and red algae(1,2). These large protein complexes capture incident sunlight and transfer the energy through a network of embedded pigment molecules called bilins to the photosynthetic reaction centres. However, light harvesting must also be balanced against the risks of photodamage. A known mode of photoprotection is mediated by orange carotenoid protein (OCP), which binds to PBS when light intensities are high to mediate photoprotective, non-photochemical quenching(3-6). Here we use cryogenic electron microscopy to solve four structures of the 6.2 MDa PBS, with and without OCP bound, from the model cyanobacterium Synechocystis sp. PCC 6803. The structures contain a previously undescribed linker protein that binds to the membrane-facing side of PBS. For the unquenched PBS, the structures also reveal three different conformational states of the antenna, two previously unknown. The conformational states result from positional switching of two of the rods and may constitute a new mode of regulation of light harvesting. Only one of the three PBS conformations can bind to OCP, which suggests that not every PBS is equally susceptible to non-photochemical quenching. In the OCP-PBS complex, quenching is achieved through the binding of four 34 kDa OCPs organized as two dimers. The complex reveals the structure of the active form of OCP, in which an approximately 60 angstrom displacement of its regulatory carboxy terminal domain occurs. Finally, by combining our structure with spectroscopic properties(7), we elucidate energy transfer pathways within PBS in both the quenched and light-harvesting states. Collectively, our results provide detailed insights into the biophysical underpinnings of the control of cyanobacterial light harvesting. The data also have implications for bioengineering PBS regulation in natural and artificial light-harvesting systems.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

Projekt

<a href="/cs/project/GX19-28323X" target="_blank" >GX19-28323X: Vztah mezi strukturou a funkcí karotenoidů: Nové cesty k řešení nezodpovězených otázek</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Nature

ISSN

0028-0836

e-ISSN

1476-4687

Svazek periodika

609

Číslo periodika v rámci svazku

7928

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

835-845

Kód UT WoS článku

000848083000005

EID výsledku v databázi Scopus

2-s2.0-85137252739