A specific cholesterol binding site is established by the 2.8 A structure of the human beta2-adrenergic receptor.
The role of cholesterol in eukaryotic membrane protein function has been attributed primarily to an influence on membrane fluidity and curvature. We present the 2.8 A resolution crystal structure of a thermally stabilized human beta(2)-adrenergic receptor bound to cholesterol and the partial inverse agonist timolol. The receptors pack as monomers in an antiparallel association with two distinct cholesterol molecules bound per receptor, but not in the packing interface, thereby indicating a structurally relevant cholesterol-binding site between helices I, II, III, and IV. Thermal stability analysis using isothermal denaturation confirms that a cholesterol analog significantly enhances the stability of the receptor. A consensus motif is defined that predicts cholesterol binding for 44% of human class A receptors, suggesting that specific sterol binding is important to the structure and stability of other G protein-coupled receptors, and that this site may provide a target for therapeutic discovery.
Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Michael A
MA
Hanson
Vadim
V
Cherezov
Mark T
MT
Griffith
Christopher B
CB
Roth
Veli-Pekka
VP
Jaakola
Ellen Y T
EY
Chien
Jeffrey
J
Velasquez
Peter
P
Kuhn
Raymond C
RC
Stevens
D001665:Binding Sites; D002784:Cholesterol / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006801:Humans; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D018343:Receptors, Adrenergic, beta-2 / Q000737:chemistry*; D013696:Temperature; D013999:Timolol / Q000737:chemistry
D018343:Receptors, Adrenergic, beta-2; D013999:Timolol; D002784:Cholesterol