The photocycle of orange carotenoid protein conceals distinct intermediates and asynchronous changes in the carotenoid and protein components.

ABSTRACT: The 35-kDa Orange Carotenoid Protein (OCP) is responsible for photoprotection in cyanobacteria. It acts as a light intensity sensor and efficient quencher of phycobilisome excitation. Photoactivation triggers large-scale conformational rearrangements to convert OCP from the orange OCP^O state to the red active signaling state, OCP^R, as demonstrated by various structural methods. Such rearrangements imply a complete, yet reversible separation of structural domains and translocation of the carotenoid. Recently, dynamic crystallography of OCP^O suggested the existence of photocycle intermediates with small-scale rearrangements that may trigger further transitions. In this study, we took advantage of single 7 ns laser pulses to study carotenoid absorption transie

SUBMITTER: Maksimov EG 

PROVIDER: S-EPMC5686206 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature