Solution Structure Analysis of the HPV16 E6 Oncoprotein Reveals a Self-Association Mechanism Required for E6-Mediated Degradation of p53.Zanier, K., Ould M'hamed Ould Sidi, A., Boulade-Ladame, C., Rybin, V., Chappelle, A., Atkinson, A., Kieffer, B., Trave, G.
(2012) Structure 20: 604-617
- PubMed: 22483108
- DOI: 10.1016/j.str.2012.02.001
- Primary Citation of Related Structures:  2LJX, 2LJZ
- PubMed Abstract:
The viral oncoprotein E6 is an essential factor for cervical cancers induced by "high-risk" mucosal HPV. Among other oncogenic activities, E6 recruits the ubiquitin ligase E6AP to promote the ubiquitination and subsequent proteasomal degradation of p ...
The viral oncoprotein E6 is an essential factor for cervical cancers induced by "high-risk" mucosal HPV. Among other oncogenic activities, E6 recruits the ubiquitin ligase E6AP to promote the ubiquitination and subsequent proteasomal degradation of p53. E6 is prone to self-association, which long precluded its structural analysis. Here we found that E6 specifically dimerizes through its N-terminal domain and that disruption of the dimer interface strongly increases E6 solubility. This allowed us to raise structural data covering the entire HPV16 E6 protein, including the high-resolution NMR structures of the two zinc-binding domains of E6 and a robust data-driven model structure of the N-terminal domain homodimer. Interestingly, homodimer interface mutations that disrupt E6 self-association also inactivate E6-mediated p53 degradation. These data suggest that E6 needs to self-associate via its N-terminal domain to promote the polyubiquitination of p53 by E6AP.
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