Sensory rhodopsin-2 (SR-2) is a 7-transmembrane 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.
Features
| 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
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| 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.
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