How does the mutant CCR5
receptor confer resistance to HIV
infection?

A genetic mutation known as CCR5-delta 32 is responsible for the two types of HIV resistance that exist. CCR5-delta 32 hampers HIV's ability to infiltrate immune cells. The mutation causes the CCR5 co-receptor on the outside of cells to develop smaller than usual and no longer sit outside of the cell.

Small molecule antagonists of CCR5 that bind to CCR5 within a pouch created by the seven membrane-spanning hydrophobic helices, stabilize the receptor conformation and prevent HIV binding to the extracellular domains, namely to the N-terminus and ECL-2, thereby blocking gp41-mediated fusion and subsequent viral replication

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands