4JR8

Crystal structure of cruxrhodopsin-3 from Haloarcula vallismortis at 2.3 angstrom resolution

4JR8 の概要

• エントリーDOI: 10.2210/pdb4jr8/pdb
• 関連するPDBエントリー: 1iw6
• 分子名称: Cruxrhodopsin-3, RETINAL, BACTERIORUBERIN, ... (4 entities in total)
• 機能のキーワード: protein-bacteioruberin complex, seven transmembrane alpha helices, light-driven proton pump, membrane, proton transport
• 由来する生物種: Haloarcula vallismortis
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: P94854
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 27892.80

構造登録者

Kouyama, T.,Chan, S.K. (登録日: 2013-03-21, 公開日: 2014-03-26, 最終更新日: 2024-11-06)

主引用文献

Chan, S.K.,Kitajima-Ihara, T.,Fujii, R.,Gotoh, T.,Murakami, M.,Ihara, K.,Kouyama, T.
Crystal structure of Cruxrhodopsin-3 from Haloarcula vallismortis
Plos One, 9:e108362-e108362, 2014

PubMed Abstract: Cruxrhodopsin-3 (cR3), a retinylidene protein found in the claret membrane of Haloarcula vallismortis, functions as a light-driven proton pump. In this study, the membrane fusion method was applied to crystallize cR3 into a crystal belonging to space group P321. Diffraction data at 2.1 Å resolution show that cR3 forms a trimeric assembly with bacterioruberin bound to the crevice between neighboring subunits. Although the structure of the proton-release pathway is conserved among proton-pumping archaeal rhodopsins, cR3 possesses the following peculiar structural features: 1) The DE loop is long enough to interact with a neighboring subunit, strengthening the trimeric assembly; 2) Three positive charges are distributed at the cytoplasmic end of helix F, affecting the higher order structure of cR3; 3) The cytoplasmic vicinity of retinal is more rigid in cR3 than in bacteriorhodopsin, affecting the early reaction step in the proton-pumping cycle; 4) the cytoplasmic part of helix E is greatly bent, influencing the proton uptake process. Meanwhile, it was observed that the photobleaching of retinal, which scarcely occurred in the membrane state, became significant when the trimeric assembly of cR3 was dissociated into monomers in the presence of an excess amount of detergent. On the basis of these observations, we discuss structural factors affecting the photostabilities of ion-pumping rhodopsins.

PubMed: 25268964
DOI: 10.1371/journal.pone.0108362

実験手法

X-RAY DIFFRACTION (2.3 Å)