Chemokine receptors ligand structure

Chemokines are small chemotactic cytokines that act as important messenger molecules between cells of the immune system. Chemokines produce their effects by activating a family of G-protein-coupled receptors. Chemokine receptors are all seven-transmembrane glycoproteins that are structurally related. They may be characterized into those that bind to specific ligands, or those that bind several chemokine ligands. There are also virally encoded (viral) chemokine receptors that represent shared receptors that have been transduced into the viral genome during evolutionary history (Premack and SchaU 1996). 

The Structural Basis for Ligand Recognition by Chemokine Receptors... 

Fig. 4. Schematic illustration of chemokine-receptor interactions. The transmembrane helices of the receptor, shown as blue tubes, were derived from the structure of rhodopsin (PDB code 1L9H). The chemokine (pink) and the N-terminal extracellular domain of the receptor were derived from the IL8-CXCR1 peptide complex shown in Fig. 5 (PDB code lILP). Except for the N-terminus, the loops of the receptor are not displayed. The figure illustrates the relative size of the receptor and ligand, and the interaction of the receptor N-terminus along one face of the chemokine. The interaction orients the N-terminal signal domain towards the receptor as displayed here it is oriented towards the helical bundle, which may or may not be correct for some chemokines. (See Color Insert.)...

Clark-Lewis, 1., Mattioli, 1., Gong, J. H., and Loetscher, P. (2003). Structure-function relationship between the human chemokine receptor CXCR3 and its ligands. /. Biol. Chem. 278, 289-295. 

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