Marta Pérez-Illana Anna Schachner Mercedes Hernando-Pérez Gabriela N. Condezo Alberto Paradela Marta Martínez Roberto Marabini Michael Hess Carmen San Martín eng Public Library of Science 2025 © 2025 Pérez-Illana et al open access Documento PDF Articolo scientifico Open Access Text journal article doi:10.1371/journal.ppat.1013553 Text Wissenschaftlicher Artikel http://creativecommons.org/licenses/by/4.0/ High-resolution structural studies have mainly focused on two out of the six adenovirus genera: mastadenoviruses and atadenoviruses. Here we report the high-resolution structure of an aviadenovirus, the poultry pathogen fowl adenovirus serotype 4 (FAdV-C4). FAdV-C4 virions are highly thermostable, despite lacking minor coat and core proteins shown to stabilize the mast- and atadenovirus particles, having no genus-specific cementing proteins, and packaging a 25% longer genome. Unique structural features of the FAdV-C4 hexon include a large insertion at the trimer equatorial region, and a long N-terminal tail. Protein IIIa conformation is closer to atadenoviruses than to mastadenoviruses, while protein VIII diverges from all previously reported structures. We interpret these differences in light of adenovirus evolution. Finally, we discuss the possible role of core composition in determining capsid stability properties. These results enlarge our view on the structural diversity of adenoviruses, and provide useful information to counteract fowl pathogens or use non-human adenoviruses as vectors. Viral Structure Protein Interactions Monomers Bird Genomics Protein Structure Virions Adenoviruses Viral Packaging PLOS Pathogens application/pdf Aviadenovirus structure: A highly thermostable capsid in the absence of stabilizing proteins https://phaidra.vetmeduni.ac.at/o:5072