Structural and electrostatic characterization of pariacoto virus: implications for viral assembly.
We present the first all-atom model for the structure of a T = 3 virus, pariacoto virus (PaV), which is a nonenveloped, icosahedral RNA virus and a member of the Nodaviridae family. The model is an extension of the crystal structure, which reveals about 88% of the protein structure but only about 35% of the RNA structure. New modeling methods, combining coarse-grained and all-atom approaches, were required for developing the model. Evaluation of alternative models confirms our earlier observation that the polycationic N- and C-terminal tails of the capsid proteins must penetrate deeply into the core of the virus, where they stabilize the structure by neutralizing a substantial fraction of the RNA charge. This leads us to propose a model for the assembly of small icosahedral RNA viruses: nonspecific binding of the protein tails to the RNA leads to a collapse of the complex, in a fashion reminiscent of DNA condensation. The globular protein domains are excluded from the condensed phase but are tethered to it, so they accumulate in a shell around the condensed phase, where their concentration is high enough to trigger oligomerization and formation of the mature virus.
Devkota
Batsal
B
School of Biology, Georgia Institute of Technology, Atlanta, GA 30332-0230, USA.
Petrov
Anton S
AS
Lemieux
Sébastien
S
Boz
Mustafa Burak
MB
Tang
Liang
L
Schneemann
Anette
A
Johnson
John E
JE
Harvey
Stephen C
SC
D016679:Genome, Viral / Q000235:genetics; D008958:Models, Molecular; D030381:Nodaviridae / Q000737:chemistry* / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry; D055672:Static Electricity; D019065:Virus Assembly
D012367:RNA, Viral