Adenovirus penton base protein

Adenovirus penton base protein is a major capsid protein of adenoviruses that self-associates into pentamers located at the 12 vertices of the icosahedral virion, where each penton base associates noncovalently with a trimeric fiber protein to form the viral vertex complex. It has a jellyroll β-barrel basal domain and a distal insertion domain and frequently contains an exposed Arg-Gly-Asp (RGD) motif in a flexible surface loop that engages host αvβ5 and related integrins. Functionally, after the fiber protein binds a primary cell-surface receptor (such as CAR, CD46, or other receptors depending on serotype), the penton base mediates secondary attachment to integrins, triggering clathrin-mediated endocytosis and sometimes macropinocytosis, thereby promoting viral internalization into host cells. The penton protein is shed during endosomal acidification as the virus disassembles, and its structural and receptor-binding properties influence adenovirus tropism, virulence, and the performance and safety profile of adenoviral vectors used for vaccination and gene therapy.

Other names

adenovirus penton proteinpenton basepenton base proteinadenoviral penton baseadenovirus L2 penton proteinmajor capsid penton protein