A 12 Å carotenoid translocation in a photoswitch associated with cyanobacterial photoprotection

• Autores: Ryan L. Leverenz, Markus Sutter, Adjélé Wilson
• Localización: Science, ISSN 0036-8075, Vol. 348, Nº 6242, 2015, págs. 1463-1466
• Idioma: inglés
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• Resumen

  • Pigment-protein and pigment-pigment interactions are of fundamental importance to the light-harvesting and photoprotective functions essential to oxygenic photosynthesis. The orange carotenoid protein (OCP) functions as both a sensor of light and effector of photoprotective energy dissipation in cyanobacteria. We report the atomic-resolution structure of an active form of the OCP consisting of the N-terminal domain and a single noncovalently bound carotenoid pigment. The crystal structure, combined with additional solution-state structural data, reveals that OCP photoactivation is accompanied by a 12 angstrom translocation of the pigment within the protein and a reconfiguration of carotenoid-protein interactions. Our results identify the origin of the photochromic changes in the OCP triggered by light and reveal the structural determinants required for interaction with the light-harvesting antenna during photoprotection.