2Z73

Crystal structure of squid rhodopsin

2Z73 の概要

• エントリーDOI: 10.2210/pdb2z73/pdb
• 分子名称: Rhodopsin, octyl beta-D-glucopyranoside, RETINAL, ... (8 entities in total)
• 機能のキーワード: visual pigment, gq-type, g-protein coupled receptor, chromophore, glycoprotein, lipoprotein, membrane, palmitate, phosphorylation, photoreceptor protein, retinal protein, sensory transduction, transducer, transmembrane, vision, membrane protein
• 由来する生物種: Todarodes pacificus (Japanese flying squid)
• 細胞内の位置: Membrane; Multi-pass membrane protein: P31356
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 103432.12

構造登録者

Murakami, M.,Kouyama, T. (登録日: 2007-08-13, 公開日: 2008-05-13, 最終更新日: 2024-10-16)

主引用文献

Murakami, M.,Kouyama, T.
Crystal structure of squid rhodopsin.
Nature, 453:363-367, 2008

PubMed Abstract: Invertebrate phototransduction uses an inositol-1,4,5-trisphosphate signalling cascade in which photoactivated rhodopsin stimulates a G(q)-type G protein, that is, a class of G protein that stimulates membrane-bound phospholipase Cbeta. The same cascade is used by many G-protein-coupled receptors, indicating that invertebrate rhodopsin is a prototypical member. Here we report the crystal structure of squid (Todarodes pacificus) rhodopsin at 2.5 A resolution. Among seven transmembrane alpha-helices, helices V and VI extend into the cytoplasmic medium and, together with two cytoplasmic helices, they form a rigid protrusion from the membrane surface. This peculiar structure, which is not seen in bovine rhodopsin, seems to be crucial for the recognition of G(q)-type G proteins. The retinal Schiff base forms a hydrogen bond to Asn 87 or Tyr 111; it is far from the putative counterion Glu 180. In the crystal, a tight association is formed between the amino-terminal polypeptides of neighbouring monomers; this intermembrane dimerization may be responsible for the organization of hexagonally packed microvillar membranes in the photoreceptor rhabdom.

PubMed: 18480818
DOI: 10.1038/nature06925

実験手法

X-RAY DIFFRACTION (2.5 Å)