Sensory rhodopsin-2 (SR-2) from N. pharaonis 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, 100 µg and purified from E. coli as a his-tagged protein.