4XB5: Structure of orange carotenoid protein binding canthaxanthin

Citation:
Abstract
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.
PDB ID: 4XB5Download
MMDB ID: 130924
PDB Deposition Date: 2014/12/16
Updated in MMDB: 2015/09
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 4XB5: monomeric; determined by author
Molecular Components in 4XB5
Label Count Molecule
Protein (1 molecule)
1
Orange Carotenoid-binding Protein
Molecule annotation
Chemicals (2 molecules)
1
1
2
1
* Click molecule labels to explore molecular sequence information.

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