5HGR

Structure of Anabaena (Nostoc) sp. PCC 7120 Orange Carotenoid Protein binding canthaxanthin

5HGR の概要

• エントリーDOI: 10.2210/pdb5hgr/pdb
• 関連するPDBエントリー: 4XB5
• 分子名称: Orange Carotenoid Protein (OCP), beta,beta-carotene-4,4'-dione (3 entities in total)
• 機能のキーワード: carotenoid, photoprotection, cyanobacteria, carotenoid binding protein
• 由来する生物種: Nostoc sp. (strain PCC 7120 / UTEX 2576)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 73534.10

構造登録者

Sutter, M.,Leverenz, R.L.,Kerfeld, C.A. (登録日: 2016-01-08, 公開日: 2016-11-16, 最終更新日: 2024-03-06)

主引用文献

Lopez-Igual, R.,Wilson, A.,Leverenz, R.L.,Melnicki, M.R.,Bourcier de Carbon, C.,Sutter, M.,Turmo, A.,Perreau, F.,Kerfeld, C.A.,Kirilovsky, D.
Different Functions of the Paralogs to the N-Terminal Domain of the Orange Carotenoid Protein in the Cyanobacterium Anabaena sp. PCC 7120.
Plant Physiol., 171:1852-1866, 2016

PubMed Abstract: The photoactive Orange Carotenoid Protein (OCP) is involved in cyanobacterial photoprotection. Its N-terminal domain (NTD) is responsible for interaction with the antenna and induction of excitation energy quenching, while the C-terminal domain is the regulatory domain that senses light and induces photoactivation. In most nitrogen-fixing cyanobacterial strains, there are one to four paralogous genes coding for homologs to the NTD of the OCP. The functions of these proteins are unknown. Here, we study the expression, localization, and function of these genes in Anabaena sp. PCC 7120. We show that the four genes present in the genome are expressed in both vegetative cells and heterocysts but do not seem to have an essential role in heterocyst formation. This study establishes that all four Anabaena NTD-like proteins can bind a carotenoid and the different paralogs have distinct functions. Surprisingly, only one paralog (All4941) was able to interact with the antenna and to induce permanent thermal energy dissipation. Two of the other Anabaena paralogs (All3221 and Alr4783) were shown to be very good singlet oxygen quenchers. The fourth paralog (All1123) does not seem to be involved in photoprotection. Structural homology modeling allowed us to propose specific features responsible for the different functions of these soluble carotenoid-binding proteins.

PubMed: 27208286
DOI: 10.1104/pp.16.00502

実験手法

X-RAY DIFFRACTION (1.681 Å)