Intracellular view of Beta 2 Adrenergic Receptor (B2AR) in the active conformation [PDB:3SN6]. B2AR is member of the G-protein coupled receptor (GPCR) superfamily of transmembrane cell surface receptors, Stabilizing interaction between arginine (R) at position 131 in the DRY motif in the third transmembrane helix (TM3) and tyrosine (Y) in the NPxxY motif in the seventh transmembrane helix (TM7) help to hold the receptor in the active conformation.