Natural CCR5 mutants.

The putative transmembrane organization of CCR5 is represented, as well as the location and the nature of the CCR5 natural mutations (in black) analyzed in this study. Extracellular loops (ECL), intracellular loops (ICL), and transmembrane domains (TM) are numbered. Disulfide bonds linking together CCR5 extracellular domains (C20-C269 and C101-C178) as well as the epitopes recognized by the MAbs 2D7, MC-5, and CTC5 are indicated. The 55 523 MAb recognizes a conformational epitope that includes the N-terminal domain and second ECL.