3AM6

Crystal structure of the proton pumping rhodopsin AR2 from marine alga Acetabularia acetabulum

3AM6 の概要

• エントリーDOI: 10.2210/pdb3am6/pdb
• 関連するPDBエントリー: 1C3W 1XIO
• 分子名称: rhodopsin-2, RETINAL, CHOLESTEROL (3 entities in total)
• 機能のキーワード: seven trans-membrane, transport protein
• 由来する生物種: Acetabularia acetabulum (Mermaid's wine glass)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 106483.65

構造登録者

Wada, T.,Yokoyama, S. (登録日: 2010-08-16, 公開日: 2011-07-06, 最終更新日: 2024-10-23)

主引用文献

Wada, T.,Shimono, K.,Kikukawa, T.,Hato, M.,Shinya, N.,Kim, S.Y.,Kimura-Someya, T.,Shirouzu, M.,Tamogami, J.,Miyauchi, S.,Jung, K.-H.,Kamo, N.,Yokoyama, S.
Crystal structure of the eukaryotic light-driven proton-pumping rhodopsin, Acetabularia rhodopsin II, from marine alga
J.Mol.Biol., 411:986-998, 2011

PubMed Abstract: Acetabularia rhodopsin (AR) is a rhodopsin from the marine plant Acetabularia acetabulum. The opsin-encoding gene from A. acetabulum, ARII, was cloned and found to be novel but homologous to that reported previously. ARII is a light-driven proton pump, as demonstrated by the existence of a photo-induced current through Xenopus oocytes expressing ARII. The photochemical reaction of ARII prepared by cell-free protein synthesis was similar to that of bacteriorhodopsin (BR), except for the lack of light-dark adaptation and the different proton release and uptake sequence. The crystal structure determined at 3.2 Å resolution is the first structure of a eukaryotic member of the microbial rhodopsin family. The structure of ARII is similar to that of BR. From the cytoplasmic side to the extracellular side of the proton transfer pathway in ARII, Asp92, a Schiff base, Asp207, Asp81, Arg78, Glu199, and Ser189 are arranged in positions similar to those of the corresponding residues directly involved in proton transfer by BR. The side-chain carboxyl group of Asp92 appears to interact with the sulfhydryl group of Cys218, which is unique to ARII and corresponds to Leu223 of BR and to Asp217 of Anabaena sensory rhodopsin. The orientation of the Arg78 side chain is opposite to the corresponding Arg82 of BR. The putative absence of water molecules around Glu199 and Arg78 may disrupt the formation of the low-barrier hydrogen bond at Glu199, resulting in the "late proton release".

PubMed: 21726566
DOI: 10.1016/j.jmb.2011.06.028

実験手法

X-RAY DIFFRACTION (3.2 Å)