Extracellular domain, of chemokine

Data from studies with other GPCRs have highlighted the importance of extracellular cysteines in ligand binding and the maintenance of the conformational integrity of the receptors. There are typically four conserved cysteine residues found on extracellular domains of chemokine receptors (see Figure 1 and Tables 2 and 3) one on the amino-terminus and one on each of the three extracellular loops. It is clear that the cysteines on extracellular loops 1 and 2 form a disulfide bond that is essential for the proper trafficking of the receptors... 

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