Fine definition of a conserved CCR5-binding region on the human immunodeficiency virus type 1 glycoprotein 120

A previous study implicated a conserved surface of the human immunodeficiency virus (HIV-1) gp120 exterior envelope glycoprotein in binding the CCR5 viral coreceptor (Rizzuto C, Wyatt R, Hernandez-Ramos N, Sun Y, Kwong PD, Hendrickson WA, and Sodroski J: Science 1998;280:1949-1953). Additional mutagenesis indicates that important residues in this region for CCR5 binding are Ile-420, Lys-421, Gln-422, Pro-438, and Gly-441, These highly conserved residues are located on two strands that connect the gp120 bridging sheet and outer domain, suggesting a mechanism whereby interdomain conformational shifts induced by CD4 binding could facilitate CCR5 binding.