7EKR

The crystal structure of Orange carotenoid binding protein 1 (OCP1)

7EKR の概要

• エントリーDOI: 10.2210/pdb7ekr/pdb
• 分子名称: Orange carotenoid protein, beta,beta-carotene-4,4'-dione (3 entities in total)
• 機能のキーワード: cyanobacteria, keto-carotenoids, cysteins, photosynthesis
• 由来する生物種: Gloeocapsa sp. PCC 7513
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 79757.34

構造登録者

Song, J.J.,Yoon, J. (登録日: 2021-04-06, 公開日: 2022-04-13, 最終更新日: 2023-11-29)

主引用文献

Han, M.H.,Yang, H.W.,Yoon, J.,Villafani, Y.,Song, J.Y.,Pan, C.H.,Park, K.,Cho, Y.,Song, J.J.,Kim, S.J.,Park, Y.I.,Park, J.
Color-Tuning Mechanism of the Lit Form of Orange Carotenoid Protein.
Mol.Cells, 46:513-525, 2023

PubMed Abstract: Orange carotenoid protein (OCP) of photosynthetic cyanobacteria binds to ketocarotenoids noncovalently and absorbs excess light to protect the host organism from light-induced oxidative damage. Herein, we found that mutating valine 40 in the α3 helix of sp. PCC 7513 (GOCP1) resulted in blue- or red-shifts of 6-20 nm in the absorption maxima of the lit forms. We analyzed the origins of absorption maxima shifts by integrating X-ray crystallography, homology modeling, molecular dynamics simulations, and hybrid quantum mechanics/molecular mechanics calculations. Our analysis suggested that the single residue mutations alter the polar environment surrounding the bound canthaxanthin, thereby modulating the degree of charge transfer in the photoexcited state of the chromophore. Our integrated investigations reveal the mechanism of color adaptation specific to OCPs and suggest a design principle for color-specific photoswitches.

PubMed: 37587751
DOI: 10.14348/molcells.2023.2186

実験手法

X-RAY DIFFRACTION (2.17 Å)