Format

Send to

Choose Destination
Biochemistry. 1999 Oct 26;38(43):14138-45.

A eukaryotic protein, NOP-1, binds retinal to form an archaeal rhodopsin-like photochemically reactive pigment.

Author information

1
Department of Microbiology and Molecular Genetics, The University of Texas Medical School, Houston, Texas 77030, USA.

Abstract

The nop-1 gene from Neurospora crassa is predicted to encode a seven-helix protein exhibiting conservation with the rhodopsins of the archaeon Halobacterium salinarum. In the work presented here we have expressed this gene heterologously in the yeast Pichia pastoris, obtaining a relatively high yield of 2.2 mg of NOP-1 protein/L of cell culture. The expressed protein is membrane-associated and forms with all-trans retinal a visible light-absorbing pigment with a 534 nm absorption maximum and approximately 100 nm half-bandwidth typical of retinylidene protein absorption spectra. Its lambda(max) indicates a protonated Schiff base linkage of the retinal. Laser flash kinetic spectroscopy demonstrates that the retinal-reconstituted pigment undergoes a photochemical reaction cycle with a near-UV-absorbing intermediate that is similar to the M intermediates produced by transient Schiff base deprotonation of the chromophore in the photocycles of bacteriorhodopsin and sensory rhodopsins I and II. The slow photocycle (seconds) and long-lived intermediates (M and O) are most similar to those of the phototaxis receptor sensory rhodopsin II. The results demonstrate a photochemically reactive member of the archaeal rhodopsin family in a eukaryotic cell.

PMID:
10571987
DOI:
10.1021/bi9916170
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center