Spectral Tuning and Excitation-Energy Transfer by Unique Carotenoids in Diatom Light-Harvesting Antenna.
J Am Chem Soc
; 146(6): 3984-3991, 2024 02 14.
Article
em En
| MEDLINE
| ID: mdl-38236721
ABSTRACT
The light-harvesting antennae of diatoms and spinach are composed of similar chromophores; however, they exhibit different absorption wavelengths. Recent advances in cryoelectron microscopy have revealed that the diatom light-harvesting antenna fucoxanthin chlorophyll a/c-binding protein (FCPII) forms a tetramer and differs from the spinach antenna in terms of the number of protomers; however, the detailed molecular mechanism remains elusive. Herein, we report the physicochemical factors contributing to the characteristic light absorption of the diatom light-harvesting antenna based on spectral calculations using an exciton model. Spectral analysis reveals the significant contribution of unique fucoxanthin molecules (fucoxanthin-S) in FCPII to the diatom-specific spectrum, and further analysis determines their essential role in excitation-energy transfer to chlorophyll. It was revealed that the specificity of these fucoxanthin-S molecules is caused by the proximity between protomers associated with the tetramerization of FCPII. The findings of this study demonstrate that diatoms employ fucoxanthin-S to harvest energy under the ocean in the absence of long-wavelength sunlight and can provide significant information about the survival strategies of photosynthetic organisms to adjust to their living environment.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carotenoides
/
Diatomáceas
/
Xantofilas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Japão