Hmdb loader
Identification
HMDB Protein ID HMDBP12376
Secondary Accession Numbers None
Name Polyprotein P1234
Synonyms
  1. P1234
  2. Non-structural polyprotein
Gene Name Not Available
Protein Type Unknown
Biological Properties
General Function Not Available
Specific Function Inactive precursor of the viral replicase, which is activated by cleavages carried out by the viral protease nsP2.The early replication complex formed by the polyprotein P123 and nsP4 synthesizes the minus-strand RNAs (antigenome) (By similarity). Polyprotein P123 is a short-lived polyprotein that accumulates during early stage of infection (Probable). As soon P123 is cleaved into mature proteins, the plus-strand RNAs synthesis begins (By similarity).The early replication complex formed by the polyprotein P123' and nsP4 synthesizes minus-strand RNAs (antigenome) (Probable). Polyprotein P123' is a short-lived polyprotein that accumulates during early stage of infection (Probable). As soon P123' is cleaved into mature proteins, the plus-strand RNAs synthesis begins (Probable).Cytoplasmic capping enzyme that catalyzes two virus-specific reactions: methyltransferase and nsP1 guanylyltransferase (By similarity). mRNA-capping is necessary since all viral RNAs are synthesized in the cytoplasm, and host capping enzymes are restricted to the nucleus (Probable). The enzymatic reaction involves a covalent link between 7-methyl-GMP and nsP1, whereas eukaryotic capping enzymes form a covalent complex only with GMP (Probable). NsP1 capping consists in the following reactions: GTP is first methylated into 7-methyl-GMP and then is covalently linked to nsP1 to form the m7GMp-nsP1 complex from which 7-methyl-GMP complex is transferred to the mRNA to create the cap structure (By similarity). NsP1 is also needed for the initiation of the minus-strand RNAs synthesis (By similarity). Probably serves as a membrane anchor for the replication complex composed of nsP1-nsP4 (By similarity). Nsp1 is needed for the initiation of the minus-strand RNAs synthesis (By similarity). Palmitoylated nsP1 is remodeling host cell cytoskeleton, and induces filopodium-like structure formation at the surface of the host cell (By similarity).Multifunctional protein whose N-terminus is part of the RNA polymerase complex and displays NTPase, RNA triphosphatase and helicase activities (By similarity). NTPase and RNA triphosphatase are involved in viral RNA capping and helicase keeps a check on the dsRNA replication intermediates (By similarity). The C-terminus harbors a protease that specifically cleaves the polyproteins and releases the mature proteins (By similarity). Required for the shutoff of minus-strand RNAs synthesis (By similarity). Inhibits host translation to ensure maximal viral gene expression and evade host immune response (By similarity).Seems to be essential for minus-strand RNAs and subgenomic 26S mRNAs synthesis (By similarity). Displays mono-ADP-ribosylhydrolase activity (By similarity). ADP-ribosylation is a post-translational modification that controls various processes of the host cell and the virus probably needs to revert it for optimal viral replication (By similarity). Binds proteins of FXR family and sequesters them into the viral RNA replication complexes thereby inhibiting the formation of host stress granules on viral mRNAs (By similarity). The nsp3-FXR complexes bind viral RNAs and probably orchestrate the assembly of viral replication complexes, thanks to the ability of FXR family members to self-assemble and bind DNA (By similarity).Seems to be essential for minus-strand RNAs and subgenomic 26S mRNAs synthesis (By similarity). Displays mono-ADP-ribosylhydrolase activity (Probable). ADP-ribosylation is a post-translational modification that controls various processes of the host cell and the virus probably needs to revert it for optimal viral replication (Probable). Binds proteins of FXR family and sequesters them into the viral RNA replication complexes thereby inhibiting the formation of host stress granules on viral mRNAs (Probable). The nsp3'-FXR complexes bind viral RNAs and probably orchestrate the assembly of viral replication complexes, thanks to the ability of FXR family members to self-assemble and bind DNA (Probable).RNA dependent RNA polymerase (By similarity). Replicates genomic and antigenomic RNA by recognizing replications specific signals. The early replication complex formed by the polyprotein P123 and nsP4 synthesizes minus-strand RNAs (By similarity). The late replication complex composed of fully processed nsP1-nsP4 is responsible for the production of genomic and subgenomic plus-strand RNAs (By similarity).
Pathways Not Available
Reactions Not Available
GO Classification
Biological Process
7-methylguanosine mRNA capping
suppression by virus of host RNA polymerase II activity
viral RNA genome replication
transcription, DNA-dependent
Cellular Component
host cell cytoplasmic vesicle membrane
host cell filopodium
host cell nucleus
host cell plasma membrane
membrane
Molecular Function
RNA-directed RNA polymerase activity
metal ion binding
RNA helicase activity
nucleoside-triphosphatase activity
ATP binding
RNA binding
cysteine-type peptidase activity
GTP binding
mRNA methyltransferase activity
polynucleotide 5'-phosphatase activity
polynucleotide adenylyltransferase activity
Cellular Location Not Available
Gene Properties
Chromosome Location Not Available
Locus Not Available
SNPs Not Available
Gene Sequence Not Available
Protein Properties
Number of Residues Not Available
Molecular Weight Not Available
Theoretical pI Not Available
Pfam Domain Function
Signals Not Available
Transmembrane Regions Not Available
Protein Sequence Not Available
GenBank ID Protein Not Available
UniProtKB/Swiss-Prot ID P36327
UniProtKB/Swiss-Prot Entry Name POLN_EEVV3
PDB IDs Not Available
GenBank Gene ID Not Available
GeneCard ID Not Available
GenAtlas ID Not Available
HGNC ID Not Available
References
General References
  1. Kinney RM, Tsuchiya KR, Sneider JM, Trent DW: Genetic evidence that epizootic Venezuelan equine encephalitis (VEE) viruses may have evolved from enzootic VEE subtype I-D virus. Virology. 1992 Dec;191(2):569-80. [PubMed:1448915 ]