Figure 20-13. Model of complex formed between isoproterenol and the β2-adrenergic receptor based on studies with mutant receptors expressed in cultured cells.

Figure 20-13Model of complex formed between isoproterenol and the β2-adrenergic receptor based on studies with mutant receptors expressed in cultured cells

The polypeptide backbone of the receptor is shown in red and green. The transmembrane helices of the receptor are labeled H1 – H7; the extracellular domains, E1 – E4; and the intracellular domains, C1 – C4. Most of the C3 domain (the long cytosolic loop between H5 and H6), C4 domain (the C-terminal tail), and N-terminal extracellular domain E1 are deleted. Isoproterenol (yellow) interacts with several residues in the receptor. Its amino group forms an ionic bond with the carboxylate side chain of aspartate 113 (D113) in H3; the catechol ring engages in hydrophobic interactions with phenylalanine 290 (F290) in H6; and two hydroxyl groups on the catechol ring hydrogen-bond to the hydroxyl groups in two serine residues (S204 and S207) in H5. [See C. D. Strader et al., 1994, Annu. Rev. Biochem. 63:101; courtesy of C. D. Strader and D. Underwood.]

From: Section 20.3, G Protein –Coupled Receptors and Their Effectors

Cover of Molecular Cell Biology
Molecular Cell Biology. 4th edition.
Lodish H, Berk A, Zipursky SL, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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