Abstract
The human immunodeficiency virus type 1 (HIV-1) protein Vif recruits the host E3 ubiquitin ligase, composed of cullin 5 (Cul5), Rbx2, Elongin B, and Elongin C (EloBC), to polyubiquitinate the antiviral protein APOBEC3G. Multiple regions in the C-terminal half of Vif interact with the E3 ligase. We have purified individual regions of Vif and investigated their thermodynamic contributions to the ligase assembly in vitro using isothermal titration calorimetry and fluorescence anisotropy. Our results quantify the high-affinity interactions between the Vif BC box and EloBC and between the Vif zinc finger and Cul5, as well as the modest interaction between the Vif cullin box and Cul5. Our purified Vif constructs also provide direct biochemical evidence that the Vif cullin box, containing the PPLP region, leads to the dimerization of Vif-EloBC complexes but not Cul5-Vif-EloBC complexes.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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APOBEC-3G Deaminase
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Amino Acid Sequence
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Cytidine Deaminase / genetics
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Cytidine Deaminase / metabolism
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HIV / genetics
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HIV / metabolism*
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Humans
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Models, Molecular
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Molecular Sequence Data
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Multiprotein Complexes / chemistry
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Multiprotein Complexes / metabolism
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Protein Binding
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Protein Conformation
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Protein Multimerization
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Thermodynamics
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Ubiquitin-Protein Ligases / chemistry*
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Ubiquitin-Protein Ligases / genetics
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Ubiquitin-Protein Ligases / metabolism*
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Ubiquitination
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vif Gene Products, Human Immunodeficiency Virus / chemistry*
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vif Gene Products, Human Immunodeficiency Virus / genetics
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vif Gene Products, Human Immunodeficiency Virus / metabolism*
Substances
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Multiprotein Complexes
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vif Gene Products, Human Immunodeficiency Virus
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vif protein, Human immunodeficiency virus 1
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Ubiquitin-Protein Ligases
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APOBEC-3G Deaminase
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APOBEC3G protein, human
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Cytidine Deaminase