4WW3

Crystal structure of the lumi intermediate of squid rhodopsin

4WW3 の概要

• エントリーDOI: 10.2210/pdb4ww3/pdb
• 分子名称: Rhodopsin, RETINAL, PALMITIC ACID, ... (8 entities in total)
• 機能のキーワード: animals, decapodiformes, inositol 1, 4, 5-trisphosphate, light, models, chemical, photochemistry, protein conformation, rhodopsin, signaling protein
• 由来する生物種: Todarodes pacificus (Japanese flying squid)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 82735.33

構造登録者

Murakami, M.,Kouyama, T. (登録日: 2014-11-10, 公開日: 2015-06-17, 最終更新日: 2024-10-30)

主引用文献

Murakami, M.,Kouyama, T.
Crystallographic Study of the LUMI Intermediate of Squid Rhodopsin
Plos One, 10:e0126970-e0126970, 2015

PubMed Abstract: Upon absorption of light, the retinal chromophore in rhodopsin isomerizes from the 11-cis to the trans configuration, initiating a photoreaction cycle. The primary photoreaction state, bathorhodopsin (BATHO), relaxes thermally through lumirhodopsin (LUMI) into a photoactive state, metarhodopsin (META), which stimulates the conjugated G-protein. Previous crystallographic studies of squid and bovine rhodopsins have shown that the structural change in the primary photoreaction of squid rhodopsin is considerably different from that observed in bovine rhodopsin. It would be expected that there is a fundamental difference in the subsequent thermal relaxation process between vertebrate and invertebrate rhodopsins. In this work, we performed crystallographic analyses of the LUMI state of squid rhodopsin using the P62 crystal. When the crystal was illuminated at 100 K with blue light, a half fraction of the protein was converted into BATHO. This reaction state relaxed into LUMI when the illuminated crystal was warmed in the dark to 170 K. It was found that, whereas trans retinal is largely twisted in BATHO, it takes on a more planar configuration in LUMI. This relaxation of retinal is accompanied by reorientation of the Schiff base NH bond, the hydrogen-bonding partner of which is switched to Asn185 in LUMI. Unlike bovine rhodopsin, the BATHO-to-LUMI transition in squid rhodopsin was accompanied by no significant change in the position/orientation of the beta-ionone ring of retinal.

PubMed: 26024518
DOI: 10.1371/journal.pone.0126970

実験手法

X-RAY DIFFRACTION (2.8 Å)