2c9f

THE QUASI-ATOMIC MODEL OF THE ADENOVIRUS TYPE 3 PENTON DODECAHEDRON

Coordinates:

OverviewOverview

The sub-viral dodecahedral particle of human adenovirus type 3, composed of the viral penton base and fiber proteins, shares an important characteristic of the entire virus: it can attach to cells and penetrate them. Structure determination of the fiberless dodecahedron by cryo-electron microscopy to 9 Angstroms resolution reveals tightly bound pentamer subunits, with only minimal interfaces between penton bases stabilizing the fragile dodecahedron. The internal cavity of the dodecahedron is approximately 80 Angstroms in diameter, and the interior surface is accessible to solvent through perforations of approximately 20 Angstroms diameter between the pentamer towers. We observe weak density beneath pentamers that we attribute to a penton base peptide including residues 38-48. The intact amino-terminal domain appears to interfere with pentamer-pentamer interactions and its absence by mutation or proteolysis is essential for dodecamer assembly. Differences between the 9 Angstroms dodecahedron structure and the adenovirus serotype 2 (Ad2) crystallographic model correlate closely with differences in sequence. The 3D structure of the dodecahedron including fibers at 16 Angstroms resolution reveals extra density on the top of the penton base that can be attributed to the fiber N terminus. The fiber itself exhibits striations that correlate with features of the atomic structure of the partial Ad2 fiber and that represent a repeat motif present in the amino acid sequence. These new observations offer important insights into particle assembly and stability, as well as the practicality of using the dodecahedron in targeted drug delivery. The structural work provides a sound basis for manipulating the properties of this particle and thereby enhancing its value for such therapeutic use.

About this StructureAbout this Structure

2C9F is a Protein complex structure of sequences from Human adenovirus 2. Full crystallographic information is available from OCA.

ReferenceReference

Structure of the dodecahedral penton particle from human adenovirus type 3., Fuschiotti P, Schoehn G, Fender P, Fabry CM, Hewat EA, Chroboczek J, Ruigrok RW, Conway JF, J Mol Biol. 2006 Feb 17;356(2):510-20. Epub 2005 Dec 9. PMID:16375921

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