Characterization of a Novel Cullin5 Binding Domain in HIV-1 Vif

Zuoxiang Xiao, Yong Xiong, Wenyan Zhang, Lindi Tan, Elana Ehrlich, Deyin Guo, Xiao Fang Yu

Research output: Contribution to journalArticlepeer-review


Human immunodeficiency virus tyoe 1 (HIV-1) Vif counteracts host restriction cytidine deaminase (APOBEC3G) A3G by co-opting the cellular ubiquitin-proteasome machinery. Vif utilizes a viral-specific BC-box to recruit ElonginB-ElonginC and a novel zinc-binding HCCH motif to recruit Cullin5 (Cul5) to form an E3 ubiquitin ligase targeting A3G for polyubiquitination and subsequently proteasomal degradation. To determine the structural requirements in HIV-1 Vif HCCH motif for Cul5 binding and Vif function, we investigated the arrangement of the His and Cys residues, the role of the spacing between them, and the requirement for the conserved residues. Our data demonstrate that exchanging Cys for His and vice versa in the highly conserved Zn-coordinating HCCH motif disrupted Vif function and interaction with Cul5. Moreover, the maintenance of both conserved residues and spacing within the HCCH motif is critical for Vif function. We have identified a "viral Cul5 box" with consensus Hx2YFxCFx4Φx2AΦx7-8Cx5H that is required for Cul5 selection and subsequent A3G degradation. This novel motif may represent a potential new target for anti-viral drug development.

Original languageEnglish (US)
Pages (from-to)541-550
Number of pages10
JournalJournal of molecular biology
Issue number3
StatePublished - Oct 26 2007
Externally publishedYes


  • HIV
  • Vif
  • cullin
  • ubiquitin ligase
  • zinc

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology


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