Structural basis for energy harvesting and dissipation in a diatom PSII-FCPII supercomplex.
Nat Plants
; 5(8): 890-901, 2019 08.
Article
en En
| MEDLINE
| ID: mdl-31358960
ABSTRACT
Light-harvesting antenna systems in photosynthetic organisms harvest solar energy and transfer it to the photosynthetic reaction centres to initiate charge-separation and electron-transfer reactions. Diatoms are one of the important groups of oxyphototrophs and possess fucoxanthin chlorophyll a/c-binding proteins (FCPs) as light harvesters. The organization and association pattern of FCP with the photosystem II (PSII) core are unknown. Here we solved the structure of PSII-FCPII supercomplexes isolated from a diatom, Chaetoceros gracilis, by single-particle cryoelectron microscopy. The PSII-FCPII forms a homodimer. In each monomer, two FCP homotetramers and three FCP monomers are associated with one PSII core. The structure reveals a highly complicated protein-pigment network that is different from the green-type light-harvesting apparatus. Comparing these two systems allows the identification of energy transfer and quenching pathways. These findings provide structural insights into not only excitation-energy transfer mechanisms in the diatom PSII-FCPII, but also changes of light harvesters between the red- and green-lineage oxyphototrophs during evolution.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Diatomeas
/
Complejo de Proteína del Fotosistema II
/
Proteínas de Unión a Clorofila
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Nat Plants
Año:
2019
Tipo del documento:
Article
País de afiliación:
Japón