Structure of the faustovirus capsid
Michael Rossmann group (Purdue University)
Thomas Klose in Michael Rossmann's laboratory at
Purdue University determined the crystal structure of the major capsid
protein of faustovirus. Faustovirus is a member of a new family of
large dsDNA viruses that shares some similarity with members of the
asfarviridae family. The outer capsid of this large virus is formed by
8280 copies of the major capsid protein and some minor proteins.
Contrary to all other large dsDNA viruses, faustovirus does not
surround its genome with an internal membrane, but instead has a second
capsid layer that is composed of an unknown protein, which makes it
likely that the virus utilizes different assembly and entry pathways
than other large viruses. Along with determining the crystal structure
of the capsid protein, the researchers reconstructed the whole virus
using images from electron cryo-microscopy, and fit the structure of
the major capsid protein into the EM map. This structure is the first
step towards understanding these unusual viral processes and provides a
foundation for further investigations. This is the largest viral
capsid currently available in the PDB.
 | Structure
of the faustovirus capsid. The outer shell is formed by 8280 copies of
the major capsid protein. Individual monomers within a trimeric
capsomer are colored in red, green, and purple. Holes visible at the
fivefold vertices of the capsid are occupied by pentameric proteins in
the complete virion, but the atomic structure of these proteins is
unknown. The enlarged area on the right shows a side-view of a
capsomer. |
Klose T, Reteno DG, Benamar S, Hollerbach A, Colson P,
La Scola B, Rossmann MG, "Structure of faustovirus, a large
dsDNA virus," Proc. Natl. Acad. Sci. USA 113 (22), 6206-6211
(2016). DOI: 10.1073/pnas.1523999113
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