Local and global structural drivers for the photoactivation of the orange carotenoid protein
Abstract
The orange carotenoid protein (OCP) is critical for the antenna-associated energy-dissipation mechanism of cyanobacteria under high light conditions. We show that light activation causes a global conformation change, the complete separation of the two domains of the OCP. Such a conformational change has been postulated to be a prerequisite for interaction with the antenna. We also identify local structural changes in residue solvent accessibility and roles for structural water molecules in activation of the OCP. By combining small-angle scattering, hydrogen-deuterium exchange, and X-ray hydroxyl radical footprinting studies, we were able to construct a model of the structural changes during the activation of the OCP with an unprecedented level of detail.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- October 2015
- DOI:
- 10.1073/pnas.1512240112
- Bibcode:
- 2015PNAS..112E5567G