Electron crystallographic analysis of two-dimensional crystals of sensory rhodopsin II: a 6.9 A projection structure.

TitleElectron crystallographic analysis of two-dimensional crystals of sensory rhodopsin II: a 6.9 A projection structure.
Publication TypeJournal Article
Year of Publication2001
AuthorsKunji, ERS, Spudich, EN, Grisshammer, R, Henderson, R, Spudich, JL
JournalJ Mol Biol
Volume308
Issue2
Pagination279-93
Date Published2001 Apr 27
ISSN0022-2836
KeywordsAnimals, Archaeal Proteins, Bacteriorhodopsins, Carotenoids, Cattle, Cryoelectron Microscopy, Crystallization, Fourier Analysis, Halobacterium salinarum, Halorhodopsins, Image Processing, Computer-Assisted, Models, Molecular, Natronobacterium, Protein Conformation, Recombinant Fusion Proteins, Rhodopsin, Sensory Rhodopsins
Abstract

Sensory rhodopsins, phototaxis receptors in Haloarchaea, were purified and reconstituted into halobacterial lipids to form photoactive two-dimensional crystals. Images of vitreous ice-embedded, flattened, tubular crystals of sensory rhodopsin II (SRII) of Natronobacterium pharaonis were recorded using a field emission gun electron cryo-microscope. Fourier components for the SRII structure were determined either from the separated image transforms from single layers that formed each side of flattened tubes, or by a deconvolution procedure when two layers were stacked in register so that they generated a single crystal lattice by superposition. Most micrographs showed significant diffraction to 6.9 A after computer processing, and the results provide the first intermediate- resolution information obtained for an archaeal sensory rhodopsin. The projection structure of SRII indicates that the helix positions match the seven-helix arrangement of the archaeal transport rhodopsins rather than that of the eukaryotic visual pigments. The structural similarity of SRII to the transport rhodopsins supports models in which the transport and signalling mechanisms of archaeal rhodopsins derive from the same retinal-driven changes in protein conformation.

DOI10.1006/jmbi.2001.4565
Alternate JournalJ. Mol. Biol.
Citation Key10.1006/jmbi.2001.4565
PubMed ID11327767
Grant ListR01GM27750 / GM / NIGMS NIH HHS / United States