Sensory rhodopsin-2 (SR-2) is a 7-transmembrane helice protein that acts as a phototaxis receptor in archaebacteria. Due to its covalently bound colored ligand, SR-2 is ideal for use as a control membrane protein, for example for crystallization assays and biochemical/biophysical experiments. We provide SR-2 of high purity, purified from E. coli as a His-tagged protein.
Figure 1: SDS-PAGE of sensory rhodopsin-2 from H. salinarum.
Figure 2: Absorbance spectrum of sensory rhodopsin-2 from H. salinarum.
|Protein ||Sensory rhodopsin-2 (SR-2, NpSRII) |
|UniProt number ||P71411 |
|Protein class ||7-transmembrane protein |
|Organism ||Halobacterium salinarum S9 |
|Sequence || |
wild-type sequence, full-length, 6x His-tag (red)
MALTTWFWVG AVGMLAGTVL PIRDCIRHPS HRRYDLVLAG ITGLAAIAYT TMGLGITATT VGDRTVYLAR YIDWLVTTPL IVLYLAMLAR PGHRTSAWLL AADVFVIAAG IAAALTTGVQ RWLFFAVGAA GYAALLYGLL GTLPRALGDD PRVRSLFVTL RNITVVLWTL YPVVWLLSPA GIGILQTEMY TIVVVYLDFI SKVAFVAFAV LGADAVSRLV AADAAAPATA EPTPDGD HHHHHH
|Affinity tags ||His-tag (C-terminus) |
|Size ||243 amino acids; 26,103 Da |
|Expression system ||E.coli |
|Purified via ||PureCube Ni-NTA Agarose |
|Buffer ||4 M NaCl, 50 mM MES pH 6.0, 0.03% dodecyl maltoside (DDM) |
|Purity (SDS-PAGE) ||>98%, see Fig. 1 |
|Absorbance ||Extinction coefficient at 497 nm: 48,000 M-1 cm-1. |
|Absorbance ||Extinction coefficient at 590 nm: 54,000 M-1 cm-1. |
|Activity ||Binding of ligand all-trans retinal, covalently bound to a lysine residue. Evaluation of UV-VIS spectrum: absorbance ratio 280 nm / 497 nm = 1.7(additional vibronic bands at 460 nm and 420 nm) |
|Function ||Photoreceptor protein undergoing a photocycle, Retinal protein, photophobic phototaxis receptor |
|Literature references || |
- Mironova, O. S., et al. "Functional characterization of sensory rhodopsin II from Halobacterium salinarum expressed in Escherichia coli." FEBS letters 579.14 (2005): 3147-3151.