Authors:
Beili Wu, Ellen Y. T. Chien, Clifford D. Mol, Gustavo Fenalti, Wei Liu, Vsevolod Katritch, Ruben Abagyan, Alexei Brooun, Peter Wells, F. Christopher Bi, Damon J. Hamel, Peter Kuhn, Tracy M. Handel, Vadim Cherezov, and Raymond C. Stevens
Summary:
Chemokine receptors are critical regulators of cell migration in the context of immune surveillance, inflammation, and development. The G protein–coupled chemokine receptor CXCR4 is specifically implicated in cancer metastasis and HIV-1 infection. Here we report five independent crystal structures of CXCR4 bound to an antagonist small molecule IT1t and a cyclic peptide CVX15 at 2.5 to 3.2 angstrom resolution. All structures reveal a consistent homodimer with an interface including helices V and VI that may be involved in regulating signaling. The location and shape of the ligand-binding sites differ from other G protein–coupled receptors and are closer to the extracellular surface. These structures provide new clues about the interactions between CXCR4 and its natural ligand CXCL12, and with the HIV-1 glycoprotein gp120.
Source:
Science; Vol. 330, No. 6007, 1066-1071 (10/07/10)