9JOU

Cryo-EM structure of the zeaxanthin-bound light-driven proton pumping rhodopsin, NM-R1

9JOU の概要

• エントリーDOI: 10.2210/pdb9jou/pdb
• EMDBエントリー: 61685
• 分子名称: Proteorhodopsin, RETINAL, HEXADECANE, ... (6 entities in total)
• 機能のキーワード: proton pump rhodopsin retinal cell-free synthesis bacterial type rhodopsin, zeaxanthin, membrane protein
• 由来する生物種: Nonlabens marinus S1-08
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 156661.61

構造登録者

Hosaka, T.,Shirouzu, M. (登録日: 2024-09-25, 公開日: 2025-07-30, 最終更新日: 2026-02-18)

主引用文献

Fujiwara, T.,Hosaka, T.,Hasegawa-Takano, M.,Nishimura, Y.,Tominaga, K.,Mori, K.,Nishino, S.,Takahashi, Y.,Uchikubo-Kamo, T.,Hanada, K.,Maoka, T.,Takaichi, S.,Inoue, K.,Shirouzu, M.,Yoshizawa, S.
Carotenoids bind rhodopsins and act as photocycle-accelerating pigments in marine Bacteroidota.
Nat Microbiol, 10:2603-2615, 2025

PubMed Abstract: Microbial rhodopsins are photoreceptor proteins widely distributed in marine microorganisms that harness light energy and support marine ecosystems. While retinal is typically the sole chromophore in microbial rhodopsins, some proteorhodopsins, which are proton-pumping rhodopsins abundant in the ocean, use carotenoid antennae to transfer light energy to retinal. However, the mechanism by which carotenoids enhance rhodopsin functions remains unclear. Here, using the marine Bacteroidota isolate Nonlabens marinus S1-08, we reconstituted complexes of rhodopsins with the carotenoid myxol and detected energy transfer to retinal in both proteorhodopsin and chloride ion-pumping rhodopsin. Carotenoid binding facilitated light harvesting and accelerated the photocycle, thereby improving the light utilization efficiency of proteorhodopsin. Cryogenic electron microscopy structural analysis further revealed the molecular architecture of the carotenoid-rhodopsin complexes. The ability to bind carotenoids is conserved in rhodopsins of the marine-dominant phylum Bacteroidota, which are widely transcribed in the photic zone. These findings reveal how carotenoids enhance rhodopsin functions in marine Bacteroidota.

PubMed: 40908369
DOI: 10.1038/s41564-025-02109-1

実験手法

ELECTRON MICROSCOPY (2.46 Å)