Fluorescent Labeling Preserving OCP Photoactivity Reveals Its Reorganization during the Photocycle.

ABSTRACT: Orange carotenoid protein (OCP), responsible for the photoprotection of the cyanobacterial photosynthetic apparatus under excessive light conditions, undergoes significant rearrangements upon photoconversion and transits from the stable orange to the signaling red state. This is thought to involve a 12-Å translocation of the carotenoid cofactor and separation of the N- and C-terminal protein domains. Despite clear recent progress, the detailed mechanism of the OCP photoconversion and associated photoprotection remains elusive. Here, we labeled the OCP of Synechocystis with tetramethylrhodamine-maleimide (TMR) and obtained a photoactive OCP-TMR complex, the fluorescence of which was highly sensitive to the protein state, showing unprecedented contrast between the orange and red states and r

SUBMITTER: Maksimov EG 

PROVIDER: S-EPMC5232356 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature