AC   MF_04128;
DC   Protein; auto
TR   HAMAP; MF_04128; -; 1; level=0
XX
Names: Rota_VP3_A
XX
ID   VP3
DE   RecName: Full=Protein VP3;
DE   Includes:
DE     RecName: Full=2',5'-phosphodiesterase;
DE              EC=3.1.4.-;
DE   Includes:
DE     RecName: Full=mRNA guanylyltransferase;
DE              EC=2.7.7.50;
DE   Includes:
DE     RecName: Full=mRNA (guanine-N(7))-methyltransferase;
DE              EC=2.1.1.56;
XX
CC   -!- FUNCTION: Multifunctional enzyme involved in mRNA capping. Catalyzes
CC       the formation of the 5' cap structure on the viral plus-strand
CC       transcripts. Specifically binds to GTP and displays guanylyltransferase
CC       and methyltransferase activities. Has affinity for ssRNA but not for
CC       dsRNA. Capping activity is non-specific and caps RNAs that initiate
CC       with either a G or an A residue. Together with VP1 polymerase, forms a
CC       VP1-VP3 complex positioned near the channels situated at each of the
CC       five-fold vertices of the core. Following infection, the outermost
CC       layer of the virus is lost, leaving a double-layered particle (DLP)
CC       made up of the core and VP6 shell. VP1 then catalyzes the transcription
CC       of fully conservative plus-strand genomic RNAs that are capped by VP3
CC       and extruded through the DLP's channels into the cytoplasm where they
CC       function as mRNAs for translation of viral proteins. DLPs probably have
CC       an RNA triphosphatase activity as well, whereas open cores do not.
CC   -!- FUNCTION: Counteracts the host innate immune response thanks to its
CC       phosphodiesterase that degrades the 5'-triphosphorylated, 2'-5' linked
CC       adenylate oligomers produced by the host cell IFN-inducible 2',5'-
CC       oligoadenylate synthetase (OAS). The host RNaseL is therefore not
CC       activated.
CC   -!- DOMAIN: Contains a bipartite N7-methyltransferase domain, a 2'-O-
CC       methyltransferase domain and a GTase/RTPase domain. The C-terminus
CC       contains a phosphodiesterase domain that degrades the 5'-
CC       triphosphorylated, 2'-5' linked adenylate oligomers produced by the
CC       host cell in response to IFN stimulation.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 5'-end diphospho-ribonucleoside in mRNA + GTP + H(+) = a 5'-
CC         end (5'-triphosphoguanosine)-ribonucleoside in mRNA + diphosphate;
CC         Xref=Rhea:RHEA:67012, Rhea:RHEA-COMP:17165, Rhea:RHEA-COMP:17166,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:33019, ChEBI:CHEBI:37565,
CC         ChEBI:CHEBI:167616, ChEBI:CHEBI:167617; EC=2.7.7.50;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a 5'-end (5'-triphosphoguanosine)-ribonucleoside in mRNA + S-
CC         adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'-
CC         triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-
CC         homocysteine; Xref=Rhea:RHEA:67008, Rhea:RHEA-COMP:17166, Rhea:RHEA-
CC         COMP:17167, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:156461,
CC         ChEBI:CHEBI:167617; EC=2.1.1.56;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5'-triphosphoadenylyl-(2'->5')-adenylyl-(2'->5')-adenosine + 2
CC         H2O = 2 AMP + ATP + 2 H(+); Xref=Rhea:RHEA:45964, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:30616, ChEBI:CHEBI:67143,
CC         ChEBI:CHEBI:456215;
CC   -!- SUBUNIT: Interacts with VP1. Interacts with VP2.
CC   -!- SUBCELLULAR LOCATION: Virion. Note=Attached inside the inner capsid as
CC       a minor component. There are about 11 to 12 copies per virion.
CC   -!- SIMILARITY: Belongs to the rotavirus VP3 family.
XX
DR   PROSITE; PS51589; SAM_MT56_VP3; 1; trigger=no
DR   Pfam; PF06929; Rotavirus_VP3; 1; trigger=no
DR   PIRSF; PIRSF004015; LigT_rotavirus; 1; trigger=no
XX
KW   Hydrolase
KW   Inhibition of host innate immune response by virus
KW   GTP-binding
KW   Host-virus interaction
KW   Methyltransferase
KW   mRNA capping
KW   mRNA processing
KW   Multifunctional enzyme
KW   Nucleotide-binding
KW   Nucleotidyltransferase
KW   RNA-binding
KW   S-adenosyl-L-methionine
KW   Transferase
KW   Viral immunoevasion
KW   Virion
XX
GO   GO:0019013; C:viral nucleocapsid
GO   GO:0005525; F:GTP binding
GO   GO:0004482; F:mRNA 5'-cap (guanine-N7-)-methyltransferase activity
GO   GO:0004484; F:mRNA guanylyltransferase activity
GO   GO:0003723; F:RNA binding
GO   GO:0016032; P:viral process
XX
FT   From: VP3_ROTSH (A2T3S5)
FT   REGION          171..245
FT                   /note="N7-methyltransferase activity"
FT   REGION          246..428
FT                   /note="2'-O-methyltransferase activity"
FT   REGION          429..555
FT                   /note="N7-methyltransferase activity"
FT   REGION          556..692
FT                   /note="GTase/RTPase activity"
FT   REGION          693..Cter
FT                   /note="2'-5'-phosphodiesterase activity"
FT   ACT_SITE        718
FT                   /note="For 2'-5'-phosphodiesterase activity"
FT   Condition: H
FT   ACT_SITE        720
FT                   /note="For 2'-5'-phosphodiesterase activity"
FT   Condition: T
FT   ACT_SITE        797
FT                   /note="For 2'-5'-phosphodiesterase activity"
FT   Condition: H
FT   ACT_SITE        799
FT                   /note="For 2'-5'-phosphodiesterase activity"
FT   Condition: T
XX
Size: 690-840;
Related: MF_04124;
Template: A2T3S5; Q6WAT6;
Scope:
 Viruses; Rotavirus
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: None
Comments: None
XX
# Revision 1.12 2024/01/30
//