3mg1
From Proteopedia
Crystal structure of the orange carotenoid protein from cyanobacteria Synechocystis sp. PCC 6803
Structural highlights
FunctionOCP_SYNY3 Acts as a photo-protectant. Essential for inhibiting white and blue-green light non-photochemical quenching (NPQ). Binding carotenoids improves OCP's intrinsic photoprotectant activity by broadening its absorption spectrum and facilitating the dissipation of absorbed energy.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe photoprotective processes of photosynthetic organisms involve the dissipation of excess absorbed light energy as heat. Photoprotection in cyanobacteria is mechanistically distinct from that in plants; it involves the orange carotenoid protein (OCP), a water-soluble protein containing a single carotenoid. The OCP is a new member of the family of blue light-photoactive proteins; blue-green light triggers the OCP-mediated photoprotective response. Here we report structural and functional characterization of the wild type and two mutant forms of the OCP, from the model organism Synechocystis PCC6803. The structural analysis provides high resolution detail of the carotenoid-protein interactions that underlie the optical properties of the OCP, unique among carotenoid-proteins in binding a single pigment per polypeptide chain. Collectively, these data implicate several key amino acids in the function of the OCP and reveal that the photoconversion and photoprotective responses of the OCP to blue-green light can be decoupled. Structural determinants underlying photoprotection in the photoactive orange carotenoid protein of cyanobacteria.,Wilson A, Kinney JN, Zwart PH, Punginelli C, D'Haene S, Perreau F, Klein MG, Kirilovsky D, Kerfeld CA J Biol Chem. 2010 Jun 11;285(24):18364-75. Epub 2010 Apr 5. PMID:20368334[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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