B1NKT1 · VP3_ROTHP

Function

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.

Catalytic activity

Features

Showing features for active site.

TypeIDPosition(s)Description
Active site718For 2'-5'-phosphodiesterase activity
Active site720For 2'-5'-phosphodiesterase activity
Active site797For 2'-5'-phosphodiesterase activity
Active site799For 2'-5'-phosphodiesterase activity

GO annotations

AspectTerm
Cellular Componentviral nucleocapsid
Molecular FunctionGTP binding
Molecular FunctionmRNA 5'-cap (guanine-N7-)-methyltransferase activity
Molecular FunctionmRNA guanylyltransferase activity
Molecular Functionoligoribonucleotidase activity
Molecular FunctionRNA binding
Biological Processdefense response to virus
Biological Processsymbiont-mediated suppression of host innate immune response
Biological Processvirus-mediated perturbation of host defense response

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Protein VP3

Including 3 domains:

  • Recommended name
    2',5'-phosphodiesterase
  • EC number
  • Recommended name
    mRNA guanylyltransferase
  • EC number
  • Recommended name
    mRNA (guanine-N(7))-methyltransferase
  • EC number

Organism names

Accessions

  • Primary accession
    B1NKT1
  • Secondary accessions
    • Q1ADF3

Proteomes

Subcellular Location

Virion
Note: Attached inside the inner capsid as a minor component. There are about 11 to 12 copies per virion.

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00003680861-835Protein VP3

Interaction

Subunit

Interacts with VP1. Interacts with VP2.

Structure

3D structure databases

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region171-245N7-methyltransferase activity
Region246-4282'-O-methyltransferase activity
Region429-555N7-methyltransferase activity
Region556-692GTase/RTPase activity
Region693-8352'-5'-phosphodiesterase activity

Domain

Contains a bipartite N7-methyltransferase domain, a 2'-O-methyltransferase 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.

Sequence similarities

Belongs to the rotavirus VP3 family.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    835
  • Mass (Da)
    97,856
  • Last updated
    2008-04-29 v1
  • Checksum
    134FE1363B1F05ED
MKVLALRHSVAQVYADTQTYLHDDSKDEYENAFLISNLTTHNILYLNYSLKTLKILNKSGIAAVEVQSPDELFALIRCNFTYDYENNIIYLHDYSYYTNNEIRTDQHWITKTDIIDYLLPGWKLTYVGYNGKNTRGHYNFSFSCQNAATDDDIIIEYIYSNELDFQNFLLRKIKERMTTSLPIARLSNRVFRDKLFPSIVNIYKKVINVGPRNESMFTFLNFPTIKQFSNGAYIVKHTIKLKQEKWLGKRVSQFDIGQYKNMLNVVTTIYYYYNLYHSKPIIYMLGSAPSYWIHDIKQYSDFTFETWDPLDTPYSTIHHKELFFDKDVNKLKDNSVLYIDIRTDRKNMDWKEWRKVVEQQTVNNLNIAYKYLSTGKAKVCCVKLTAMDLELPITAKLLHHPTTEVRSEFYAILDAWDIITIKRFIPKGVFYAFINNITTENVFIQPPFKLKASPTDYIVALYALSNDFNSRQDVINLINKQKQSLITVRMNNTFKDEPKVNFKNIYDWTFLPTDFELKDSIITSYDGCLGMFGLSISLSSKPTGNNHLFIINGTDKYYKLDQYANHMGISRRSHQIRFSESATSYSGYIFRDLSNNNFNLIGTNVENSVSGHVYNALIYYRYNYAFDLKRWIYLHSIGKVTVEGGRYYEHAPIELIYACRSAKEFAILQDDLTVLRYANEIEGYINKVYSITYADDPNYFIGIKFNSIPYEYDVKVPHLTLGVLFISDNMIHDVVTVLKKMKTELFKTEISTSYTYMLSDNIYVANASGVLSTYFKLYNMFYRNHITFGQSRMFIPHITLSFSNKQTVRIESTRLKINSIYLRKIKGETVFDMSE

Sequence caution

The sequence ABB18255.1 differs from that shown. Reason: Frameshift

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict294in Ref. 2; ABB18255

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
EF583039
EMBL· GenBank· DDBJ
ABU87848.1
EMBL· GenBank· DDBJ
Genomic RNA
DQ200932
EMBL· GenBank· DDBJ
ABB18255.1
EMBL· GenBank· DDBJ
Genomic RNA Frameshift

Similar Proteins

Disclaimer

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