2GH8

X-ray structure of a native calicivirus

Summary for 2GH8

• Entry DOI: 10.2210/pdb2gh8/pdb
• Descriptor: Capsid protein (1 entity in total)
• Functional Keywords: native calicivirus, vesivirus, icosahedral t=3 capsid, domain swapping, n-terminal arm, shell domain, protruding domain, icosahedral virus, virus
• Biological source: San Miguel sea lion virus 4
• Cellular location: Virion: P36285
• Total number of polymer chains: 3
• Total formula weight: 184934.87

Authors

Chen, R. (deposition date: 2006-03-26, release date: 2006-05-16, Last modification date: 2024-04-03)

Primary citation

Chen, R.,Neill, J.D.,Estes, M.K.,Prasad, B.V.
X-ray structure of a native calicivirus: Structural insights into antigenic diversity and host specificity.
Proc.Natl.Acad.Sci.Usa, 103:8048-8053, 2006

PubMed Abstract: Caliciviruses, grouped into four genera, are important human and veterinary pathogens with a potential for zoonosis. In these viruses, capsid-related functions such as assembly, antigenicity, and receptor interactions are predominantly encoded in a single protein that forms an icosahedral capsid. Understanding of the immunologic functions and pathogenesis of human caliciviruses in the Norovirus and Sapovirus genera is hampered by the lack of a cell culture system or animal models. Much of our understanding of these viruses, including the structure, has depended on recombinant capsids. Here we report the atomic structure of a native calicivirus from the Vesivirus genus that exhibits a broad host range possibly including humans and map immunological function onto a calicivirus structure. The vesivirus structure, despite a similar architectural design as seen in the recombinant norovirus capsid, exhibits novel features and indicates how the unique modular organization of the capsid protein with interdomain flexibility, similar to an antibody structure with a hinge and an elbow, integrates capsid-related functions and facilitates strain diversity in caliciviruses. The internally located N-terminal arm participates in a novel network of interactions through domain swapping to assist the assembly of the shell domain into an icosahedral scaffold, from which the protruding domain emanates. Neutralization epitopes localize to three hypervariable loops in the distal portion of the protruding domain surrounding a region that exhibits host-specific conservation. These observations suggest a mechanism for antigenic diversity and host specificity in caliciviruses and provide a structural framework for vaccine development.

PubMed: 16702551
DOI: 10.1073/pnas.0600421103

Experimental method

X-RAY DIFFRACTION (3.2 Å)