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. 2025 Mar 6;33(3):504-516.e4.
doi: 10.1016/j.str.2024.12.013. Epub 2025 Jan 15.

Structure of E6AP in complex with HPV16-E6 and p53 reveals a novel ordered domain important for E3 ligase activation

Sebastian Kenny  1 , Shalini Iyer  1 , Clinton A Gabel  2 , Natalia Tegenfeldt  3 , Andrew G DeMarco  4 , Mark C Hall  4 , Leifu Chang  2 , V Jo Davisson  5 , Scott Vande Pol  6 , Chittaranjan Das  7
Affiliations

Structure of E6AP in complex with HPV16-E6 and p53 reveals a novel ordered domain important for E3 ligase activation

Sebastian Kenny et al. Structure. .

Abstract

High-risk human papillomavirus E6 oncoprotein is a model system for the recognition and degradation of cellular p53 tumor suppressor protein. There remains a gap in the understanding of the ubiquitin transfer reaction, including placement of the E6AP catalytic HECT domain of the ligase concerning the p53 substrate and how E6 itself is protected from ubiquitination. We determined the cryoelectron microscopy (cryo-EM) structure of the E6AP/E6/p53 complex, related the structure to in vivo modeling of the tri-molecular complex, and identified structural interactions associated with activation of the ubiquitin ligase function. The structure reveals that the N-terminal ordered domain (NOD) in E6AP has a terminal alpha helix that mediates the interaction of the NOD with the HECT domain of E6AP and protects the HPV-E6 protein from ubiquitination. In addition, this NOD helix is required for E6AP ligase function by contributing to the affinity of the E6-E6AP association, modulating E6 substrate recognition, while displacing UbcH7.

Keywords: E3 ligase; E6AP; HPV; cryo-EM; ligase activation; targeted degradation; ubiquitin; viral factor; yeast hybrid.

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Conflict of interest statement

Declaration of interests The authors declare no competing interests.

References

    1. Hershko A, and Ciechanover A (1998). The ubiquitin system. Annu Rev Biochem 67, 425–479. 10.1146/annurev.biochem.67.1.425. - DOI - PubMed
    1. Komander D (2009). The emerging complexity of protein ubiquitination. Biochem Soc Trans 37, 937–953, 10.1042/BST0370937 - DOI - PubMed
    1. Schulman BA, and Wade Harper J (2009). Ubiquitin-like protein activation by E1 enzymes: The apex for downstream signalling pathways. Nature Reviews Molecular Cell Biology 10, 319–331, 10.1038/nrm2673. - DOI - PMC - PubMed
    1. Wenzel DM, Stoll KE, and Klevit RE (2011). E2s: Structurally economical and functionally replete. Biochem J 433, 31–42, 10.1042/BJ20100985. - DOI - PMC - PubMed
    1. Deshaies RJ, and Joazeiro CAP (2009). RING domain E3 ubiquitin ligases. Annu Rev Biochem 78, 399–434, 10.1146/annurev.biochem.78.101807.093809. - DOI - PubMed

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