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Light activation of Orange Carotenoid Protein reveals bicycle-pedal single-bond isomerization.
Chukhutsina, Volha U; Baxter, James M; Fadini, Alisia; Morgan, Rhodri M; Pope, Matthew A; Maghlaoui, Karim; Orr, Christian M; Wagner, Armin; van Thor, Jasper J.
Afiliación
  • Chukhutsina VU; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
  • Baxter JM; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
  • Fadini A; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
  • Morgan RM; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
  • Pope MA; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
  • Maghlaoui K; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK.
  • Orr CM; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
  • Wagner A; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
  • van Thor JJ; Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK. j.vanthor@imperial.ac.uk.
Nat Commun ; 13(1): 6420, 2022 10 28.
Article en En | MEDLINE | ID: mdl-36307413
Orange Carotenoid protein (OCP) is the only known photoreceptor which uses carotenoid for its activation. It is found exclusively in cyanobacteria, where it functions to control light-harvesting of the photosynthetic machinery. However, the photochemical reactions and structural dynamics of this unique photosensing process are not yet resolved. We present time-resolved crystal structures at second-to-minute delays under bright illumination, capturing the early photoproduct and structures of the subsequent reaction intermediates. The first stable photoproduct shows concerted isomerization of C9'-C8' and C7'-C6' single bonds in the bicycle-pedal (s-BP) manner and structural changes in the N-terminal domain with minute timescale kinetics. These are followed by a thermally-driven recovery of the s-BP isomer to the dark state carotenoid configuration. Structural changes propagate to the C-terminal domain, resulting, at later time, in the H-bond rupture of the carotenoid keto group with protein residues. Solution FTIR and UV/Vis spectroscopy support the single bond isomerization of the carotenoid in the s-BP manner and subsequent thermal structural reactions as the basis of OCP photoreception.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Bacterianas / Ciclismo Idioma: En Revista: Nat Commun Asunto de la revista: BIOLOGIA / CIENCIA Año: 2022 Tipo del documento: Article Pais de publicación: Reino Unido

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Proteínas Bacterianas / Ciclismo Idioma: En Revista: Nat Commun Asunto de la revista: BIOLOGIA / CIENCIA Año: 2022 Tipo del documento: Article Pais de publicación: Reino Unido