Purity > 90% as determined by SDS-PAGE. MW: 34.2kDa. Partial: 1-36aa. N-terminal 6xHis-GST-tagged. Sus scrofa (Pig). Photoreceptor required for image-forming vision at low light intensity. Required for photoreceptor cell viability after birth. Light-induced isomerization of 11-cis to all-trans retinal triggers a conformational change that activates signaling via G-proteins. Subsequent receptor phosphorylation mediates displacement of the bound G-protein alpha subunit by the arrestin SAG and terminates signaling