Structural highlights
Function
[VP2_ROTW3] Inner capsid protein that self assembles to form an icosahedral capsid with a T=2 symmetry, which consists of 120 copies of VP2, with channels at each of its five-fold vertices. This capsid constitutes the innermost concentric layer of the viral mature particle. It encapsidates the polymerase VP1, the capping enzyme VP3 and the genomic dsRNA, thereby defining the core. The innermost VP2 capsid and the intermediate VP6 capsid remain intact following cell entry to protect the dsRNA from degradation and to prevent unfavorable antiviral responses in the host cell during all the replication cycle of the virus. Nacent transcripts are transcribed within the structural confines of this double-layered particle (DLP) and are extruded through the channels at the five-fold axes. VP2 is required for the replicase activity of VP1 polymerase. It probably plays a role in the coordination of packaging and genome replication by controlling the initiation of minus-strand synthesis. Binding to the polymerase VP1 presumably activates the autoinhibited VP1-RNA complex which will start the synthesis of the complementary minus-strand (By similarity). [VP6_ROTRF] Intermediate capsid protein that self assembles to form an icosahedral capsid with a T=13 symmetry, which consists of 230 trimers of VP6, with channels at each of its five-fold vertices. This capsid constitutes the middle concentric layer of the viral mature particle. The innermost VP2 capsid and the intermediate VP6 capsid remain intact following cell entry to protect the dsRNA from degradation and to prevent unfavorable antiviral responses in the host cell during all the replication cycle of the virus. Nacent transcripts are transcribed within the structural confines of this double-layered particle (DLP) and are extruded through the channels at the five-fold axes. VP6 is required for the transcription activity of the DLP.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Rotaviruses, major causes of childhood gastroenteritis, are nonenveloped, icosahedral particles with double-strand RNA genomes. By the use of electron cryomicroscopy and single-particle reconstruction, we have visualized a rotavirus particle comprising the inner capsid coated with the trimeric outer-layer protein, VP7, at a resolution (4 A) comparable with that of X-ray crystallography. We have traced the VP7 polypeptide chain, including parts not seen in its X-ray crystal structure. The 3 well-ordered, 30-residue, N-terminal "arms" of each VP7 trimer grip the underlying trimer of VP6, an inner-capsid protein. Structural differences between free and particle-bound VP7 and between free and VP7-coated inner capsids may regulate mRNA transcription and release. The Ca(2+)-stabilized VP7 intratrimer contact region, which presents important neutralizing epitopes, is unaltered upon capsid binding.
Molecular interactions in rotavirus assembly and uncoating seen by high-resolution cryo-EM.,Chen JZ, Settembre EC, Aoki ST, Zhang X, Bellamy AR, Dormitzer PR, Harrison SC, Grigorieff N Proc Natl Acad Sci U S A. 2009 Jun 30;106(26):10644-8. Epub 2009 Jun 1. PMID:19487668[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Bican P, Cohen J, Charpilienne A, Scherrer R. Purification and characterization of bovine rotavirus cores. J Virol. 1982 Sep;43(3):1113-7. PMID:6292454
- ↑ Chen JZ, Settembre EC, Aoki ST, Zhang X, Bellamy AR, Dormitzer PR, Harrison SC, Grigorieff N. Molecular interactions in rotavirus assembly and uncoating seen by high-resolution cryo-EM. Proc Natl Acad Sci U S A. 2009 Jun 30;106(26):10644-8. Epub 2009 Jun 1. PMID:19487668
