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Annotation rule MF_04128
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General rule information [?]

Accession MF_04128
Dates 28-MAR-2018 (Created)
11-MAR-2021 (Last updated, Version 9)
Name Rota_VP3_A
Scope
Viruses; Rotavirus
Templates A2T3S5 (VP3_ROTSH); Q6WAT6 (VP3_ROTBU): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
VP3
Protein name
RecName: Full=Protein VP3;
Includes:
RecName: Full=2',5'-phosphodiesterase;
EC 3.1.4.-;
Includes:
RecName: Full=mRNA guanylyltransferase;
EC 2.7.7.50;
Includes:
RecName: Full=mRNA (guanine-N(7))-methyltransferase;
EC 2.1.1.56;

Comments [?]

Function Multifunctional enzyme involved in mRNA capping. Catalyzes the formation of the 5' cap structure on the viral plus-strand transcripts. Specifically binds to GTP and displays guanylyltransferase and methyltransferase activities. Has affinity for ssRNA but not for dsRNA. Capping activity is non-specific and caps RNAs that initiate with either a G or an A residue. Together with VP1 polymerase, forms a VP1-VP3 complex positioned near the channels situated at each of the five-fold vertices of the core. Following infection, the outermost layer of the virus is lost, leaving a double-layered particle (DLP) made up of the core and VP6 shell. VP1 then catalyzes the transcription of fully conservative plus-strand genomic RNAs that are capped by VP3 and extruded through the DLP's channels into the cytoplasm where they function as mRNAs for translation of viral proteins. DLPs probably have an RNA triphosphatase activity as well, whereas open cores do not.
Counteracts the host innate immune response thanks to its phosphodiesterase that degrades the 5'-triphosphorylated, 2'-5' linked adenylate oligomers produced by the host cell IFN-inducible 2',5'-oligoadenylate synthetase (OAS). The host RNaseL is therefore not activated.
Domain Contains a bipartite N7-methytransferase domain, a 2'-O-methytransferase domain and a GTase/RTPase domain. The C-terminus contains a phosphodiesterase domain that degrades the 5'-triphosphorylated, 2'-5' linked adenylate oligomers produced by the host cell in response to IFN stimulation.
Catalytic activity RHEA:67012: a 5'-end diphospho-ribonucleoside in mRNA + GTP + H(+) = a 5'-end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + diphosphate
EC 2.7.7.50
RHEA:67008: a 5'-end (5'-triphosphoguanosine)-(ribonucleoside) in mRNA + S-adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-homocysteine
EC 2.1.1.56
RHEA:45964: 5'-triphosphoadenylyl-(2'->5')-adenylyl-(2'->5')-adenosine + 2 H2O = 2 AMP + ATP + 2 H(+)
Subunit Interacts with VP1. Interacts with VP2.
Subcellular location Virion. Note=Attached inside the inner capsid as a minor component. There are about 11 to 12 copies per virion.
Similarity Belongs to the rotavirus VP3 family.

Keywords [?]


Gene Ontology [?]

GO:0019013; Cellular component: viral nucleocapsid.
GO:0005525; Molecular function: GTP binding.
GO:0004482; Molecular function: mRNA (guanine-N7-)-methyltransferase activity.
GO:0004484; Molecular function: mRNA guanylyltransferase activity.
GO:0003723; Molecular function: RNA binding.
GO:0016032; Biological process: viral process.

Cross-references [?]

PROSITE PS51589; SAM_MT56_VP3; 1;
Pfam PF06929; Rotavirus_VP3; 1;
PIRSF PIRSF004015; LigT_rotavirus; 1;

Features [?]

From: VP3_ROTSH (A2T3S5)
Key     From     To       Description   Tag   Condition   FTGroup
REGION     171     245       N7-methyltransferase activity        
REGION     246     428       2'-O-methyltransferase activity        
REGION     429     555       N7-methyltransferase activity        
REGION     556     692       GTase/RTPase activity        
REGION     693     Cter       2'-5'-phosphodiesterase activity        
ACT_SITE     718     718       For 2'-5'-phosphodiesterase activity     H  
ACT_SITE     720     720       For 2'-5'-phosphodiesterase activity     T  
ACT_SITE     797     797       For 2'-5'-phosphodiesterase activity     H  
ACT_SITE     799     799       For 2'-5'-phosphodiesterase activity     T  

Additional information [?]

Size range 690-840 amino acids
Related rules MF_04124 (VP3)
Fusion None