Conformational Dynamics of the HIV-Vif Protein Complex.

Human immunodeficiency virus-1 viral infectivity factor (Vif) is an intrinsically disordered protein responsible for the ubiquitination of the APOBEC3 (A3) antiviral proteins. Vif folds when it binds Cullin-RING E3 ligase 5 and the transcription cofactor CBF-β. A five-protein complex containing the substrate receptor (Vif, CBF-β, Elongin-B, Elongin-C (VCBC)) and Cullin5 (CUL5) has a published crystal structure, but dynamics of this VCBC-CUL5 complex have not been characterized.