Crystallization and crystal properties of squid rhodopsin.
Rhodopsin, a photoreceptor membrane protein in the retina, is a prototypical member of the G-protein-coupled receptor family. In this study, rhodopsin from the retina of the squid Todarodes pacificus was treated with V8 protease to remove the C-terminal extension. Truncated rhodopsin was selectively extracted from the microvillar membranes using alkyl glucoside in the presence of zinc ions and was then crystallized by the sitting-drop vapour-diffusion method. Of the various crystals obtained, hexagonal crystals grown in the presence of octylglucoside and ammonium sulfate diffracted to 2.8 A resolution. The diffraction data suggested that the crystal belongs to space group P6(2), with unit-cell parameters a = b = 122.1, c = 158.6 A. Preliminary crystallographic analysis, together with linear dichroism results, suggested that the rhodopsin dimers are packed in such a manner that their transmembrane helices are aligned nearly parallel to the c axis.
Murakami
Midori
M
Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan.
Kitahara
Rei
R
Gotoh
Toshiaki
T
Kouyama
Tsutomu
T
D000818:Animals; D003460:Crystallization; D018360:Crystallography, X-Ray; D049832:Decapodiformes / Q000648:ultrastructure; D012243:Rhodopsin / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure
D012243:Rhodopsin