Structure of the p53 degradation complex from HPV16.

Area of Science:

• Structural biology
• Virology
• Cancer research

Background:

• Human papillomavirus (HPV) contributes significantly to global cancer incidence.
• HPV oncoprotein E6 facilitates cancer by degrading the tumor suppressor p53 via interaction with E3-ligase E6AP (UBE3A).
• The E6-E6AP-p53 complex is a long-standing therapeutic target for HPV-associated cancers.

Purpose of the Study:

• To determine the high-resolution structure of the full-length E6AP protein in complex with HPV16 E6 (16E6) and p53.
• To elucidate the molecular basis of protein-protein interactions within this ternary complex.
• To provide insights for developing novel therapeutic strategies against HPV-driven cancers.

Main Methods:

• Single-particle cryo-electron microscopy (cryo-EM).
• Determination of a ~3.3 Å resolution structure of the E6AP-16E6-p53 complex.

Main Results:

• The study presents the first cryo-EM structure of the full-length E6AP, HPV16 E6, and p53 complex.
• Extensive protein-protein interactions between 16E6 and E6AP were revealed, explaining their high binding affinity.
• The structural data provides a molecular understanding of the ternary complex's formation.

Conclusions:

• The determined structure offers a detailed view of the molecular interactions critical for p53 degradation by HPV E6.
• Understanding these interactions may explain the limited success of previous therapeutic attempts.
• Reevaluation of therapeutic strategies targeting this complex is suggested for more effective cancer treatment.