7W74

Crystal structure of DTG rhodopsin from Pseudomonas putida

7W74 の概要

• エントリーDOI: 10.2210/pdb7w74/pdb
• 分子名称: Bacteriorhodopsin-like protein, RETINAL, (2S)-2,3-dihydroxypropyl (9Z)-octadec-9-enoate, ... (5 entities in total)
• 機能のキーワード: light-driven proton pump, seven transmembrane helices, retinal, dtg motif, membrane protein
• 由来する生物種: Pseudomonas putida
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 55069.80

構造登録者

Suzuki, K.,Konno, M.,Bagherzadeh, R.,Inoue, K.,Murata, T. (登録日: 2021-12-03, 公開日: 2022-02-23, 最終更新日: 2024-11-20)

主引用文献

Suzuki, K.,Del Carmen Marin, M.,Konno, M.,Bagherzadeh, R.,Murata, T.,Inoue, K.
Structural characterization of proton-pumping rhodopsin lacking a cytoplasmic proton donor residue by X-ray crystallography.
J.Biol.Chem., 298:101722-101722, 2022

PubMed Abstract: DTG/DTS rhodopsin, which was named based on a three-residue motif (DTG or DTS) that is important for its function, is a light-driven proton-pumping microbial rhodopsin using a retinal chromophore. In contrast to other light-driven ion-pumping rhodopsins, DTG/DTS rhodopsin does not have a cytoplasmic proton donor residue, such as Asp, Glu, or Lys. Because of the lack of cytoplasmic proton donor residue, proton directly binds to the retinal chromophore from the cytoplasmic solvent. However, mutational experiments that showed the complicated effects of mutations were not able to clarify the roles played by each residue, and the detail of proton uptake pathway is unclear because of the lack of structural information. To understand the proton transport mechanism of DTG/DTS rhodopsin, here we report the three-dimensional structure of one of the DTG/DTS rhodopsins, PspR from Pseudomonas putida, by X-ray crystallography. We show that the structure of the cytoplasmic side of the protein is significantly different from that of bacteriorhodopsin, the best-characterized proton-pumping rhodopsin, and large cytoplasmic cavities were observed. We propose that these hydrophilic cytoplasmic cavities enable direct proton uptake from the cytoplasmic solvent without the need for a specialized cytoplasmic donor residue. The introduction of carboxylic residues homologous to the cytoplasmic donors in other proton-pumping rhodopsins resulted in higher pumping activity with less pH dependence, suggesting that DTG/DTS rhodopsins are advantageous for producing energy and avoiding intracellular alkalization in soil and plant-associated bacteria.

PubMed: 35151692
DOI: 10.1016/j.jbc.2022.101722

実験手法

X-RAY DIFFRACTION (2.84 Å)