Quaternary contact in the initial interaction of CD4 with the HIV-1 envelope trimer.

Journal Article (Journal Article)

Binding of the gp120 envelope (Env) glycoprotein to the CD4 receptor is the first step in the HIV-1 infectious cycle. Although the CD4-binding site has been extensively characterized, the initial receptor interaction has been difficult to study because of major CD4-induced structural rearrangements. Here we used cryogenic electron microscopy (cryo-EM) to visualize the initial contact of CD4 with the HIV-1 Env trimer at 6.8-Å resolution. A single CD4 molecule is embraced by a quaternary HIV-1-Env surface formed by coalescence of the previously defined CD4-contact region with a second CD4-binding site (CD4-BS2) in the inner domain of a neighboring gp120 protomer. Disruption of CD4-BS2 destabilized CD4-trimer interaction and abrogated HIV-1 infectivity by preventing the acquisition of coreceptor-binding competence. A corresponding reduction in HIV-1 infectivity occurred after the mutation of CD4 residues that interact with CD4-BS2. Our results document the critical role of quaternary interactions in the initial HIV-Env-receptor contact, with implications for treatment and vaccine design.

Full Text

Duke Authors

Cited Authors

  • Liu, Q; Acharya, P; Dolan, MA; Zhang, P; Guzzo, C; Lu, J; Kwon, A; Gururani, D; Miao, H; Bylund, T; Chuang, G-Y; Druz, A; Zhou, T; Rice, WJ; Wigge, C; Carragher, B; Potter, CS; Kwong, PD; Lusso, P

Published Date

  • April 2017

Published In

Volume / Issue

  • 24 / 4

Start / End Page

  • 370 - 378

PubMed ID

  • 28218750

Pubmed Central ID

  • PMC5798227

Electronic International Standard Serial Number (EISSN)

  • 1545-9985

Digital Object Identifier (DOI)

  • 10.1038/nsmb.3382


  • eng

Conference Location

  • United States