Aviadenovirus structure: A highly thermostable capsid in the absence of stabilizing proteins

DOI: 10.1371/journal.ppat.1013553

Authors: Marta Perez-Illana (Centro Nacional de Biotecnología (CNB-CSIC)) , Anna Schachner (University of Veterinary Medicine (Austria)) , Mercedes Hernando-Perez (Centro Nacional de Biotecnología (CNB-CSIC)) , Gabriela N. Condezo (Centro Nacional de Biotecnología (CNB-CSIC)) , Alberto Paradela (Centro Nacional de Biotecnología (CNB-CSIC)) , Marta Martínez (Centro Nacional de Biotecnología (CNB-CSIC)) , Roberto Marabini (Universidad Autónoma de Madrid) , Michael Hess (University of Veterinary Medicine) , Carmen San Martín (Centro Nacional de Biotecnología (CNB-CSIC))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Plos Pathogens , VOL 21

State: Published (Approved)
Published: October 2025
Diamond Proposal Number(s): 15997

Abstract: 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.

Journal Keywords: Viral packaging; Adenoviruses; Virions; Protein structure; Bird genomics; Monomers; Protein interactions; Viral structure

Diamond Keywords: Viruses

Subject Areas: Biology and Bio-materials

Diamond Offline Facilities: Electron Bio-Imaging Centre (eBIC)
Instruments: Krios II-Titan Krios II at Diamond

Added On: 15/10/2025 13:58

Documents:
journal.ppat.1013553.pdf

Discipline Tags:

Evolutionary science Pathogens Health & Wellbeing Structural biology Life Sciences & Biotech Veterinary Medicine

Technical Tags:

Microscopy Electron Microscopy (EM) Cryo Electron Microscopy (Cryo EM)