POLN_SINDO
ID POLN_SINDO Reviewed; 2515 AA.
AC P27283;
DT 01-AUG-1992, integrated into UniProtKB/Swiss-Prot.
DT 10-APR-2019, sequence version 2.
DT 03-AUG-2022, entry version 152.
DE RecName: Full=Polyprotein P1234;
DE Short=P1234;
DE AltName: Full=Non-structural polyprotein;
DE Contains:
DE RecName: Full=Polyprotein P123';
DE Short=P123';
DE Contains:
DE RecName: Full=Polyprotein P123;
DE Short=P123;
DE Contains:
DE RecName: Full=mRNA-capping enzyme nsP1;
DE EC=2.1.1.- {ECO:0000250|UniProtKB:P27282};
DE EC=2.7.7.- {ECO:0000250|UniProtKB:P03317};
DE AltName: Full=Non-structural protein 1;
DE Contains:
DE RecName: Full=Protease nsP2;
DE EC=3.1.3.33 {ECO:0000250|UniProtKB:P08411};
DE EC=3.4.22.- {ECO:0000250|UniProtKB:Q8JUX6};
DE EC=3.6.1.15 {ECO:0000250|UniProtKB:Q8JUX6};
DE EC=3.6.4.13 {ECO:0000250|UniProtKB:Q8JUX6};
DE AltName: Full=Non-structural protein 2;
DE Short=nsP2;
DE Contains:
DE RecName: Full=Non-structural protein 3';
DE Short=nsP3';
DE EC=3.1.3.84 {ECO:0000305};
DE Contains:
DE RecName: Full=Non-structural protein 3;
DE Short=nsP3;
DE EC=3.1.3.84 {ECO:0000250|UniProtKB:Q8JUX6};
DE Contains:
DE RecName: Full=RNA-directed RNA polymerase nsP4;
DE EC=2.7.7.19 {ECO:0000250|UniProtKB:P03317};
DE EC=2.7.7.48 {ECO:0000255|PROSITE-ProRule:PRU00539};
DE AltName: Full=Non-structural protein 4;
DE Short=nsP4;
OS Sindbis virus subtype Ockelbo (strain Edsbyn 82-5) (OCKV) (Ockelbo virus).
OC Viruses; Riboviria; Orthornavirae; Kitrinoviricota; Alsuviricetes;
OC Martellivirales; Togaviridae; Alphavirus.
OX NCBI_TaxID=31699;
OH NCBI_TaxID=48156; Acrocephalus scirpaceus (Eurasian reed-warbler).
OH NCBI_TaxID=7158; Aedes.
OH NCBI_TaxID=53527; Culex.
OH NCBI_TaxID=9606; Homo sapiens (Human).
OH NCBI_TaxID=45807; Motacilla alba (White wagtail) (Pied wagtail).
OH NCBI_TaxID=177155; Streptopelia turtur.
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX PubMed=1673813; DOI=10.1016/0042-6822(91)90616-j;
RA Shirako Y., Niklasson B., Dalrymple J.M., Strauss E.G., Strauss J.H.;
RT "Structure of the Ockelbo virus genome and its relationship to other
RT Sindbis viruses.";
RL Virology 182:753-764(1991).
CC -!- FUNCTION: [Polyprotein P1234]: Inactive precursor of the viral
CC replicase, which is activated by cleavages carried out by the viral
CC protease nsP2. {ECO:0000250|UniProtKB:Q8JUX6}.
CC -!- FUNCTION: [Polyprotein P123]: The early replication complex formed by
CC the polyprotein P123 and nsP4 synthesizes minus-strand RNAs (By
CC similarity). As soon P123 is cleaved into mature proteins, the plus-
CC strand RNAs synthesis begins (By similarity).
CC {ECO:0000250|UniProtKB:P03317}.
CC -!- FUNCTION: [Polyprotein P123']: The early replication complex formed by
CC the polyprotein P123' and nsP4 synthesizes minus-strand RNAs
CC (Probable). Polyprotein P123' is a short-lived polyprotein that
CC accumulates during early stage of infection (Probable). As soon P123'
CC is cleaved into mature proteins, the plus-strand RNAs synthesis begins
CC (Probable). {ECO:0000305}.
CC -!- FUNCTION: [mRNA-capping enzyme nsP1]: Cytoplasmic capping enzyme that
CC catalyzes two virus-specific reactions: methyltransferase and nsP1
CC guanylyltransferase (By similarity). mRNA-capping is necessary since
CC all viral RNAs are synthesized in the cytoplasm, and host capping
CC enzymes are restricted to the nucleus (Probable). The enzymatic
CC reaction involves a covalent link between 7-methyl-GMP and nsP1,
CC whereas eukaryotic capping enzymes form a covalent complex only with
CC GMP (By similarity). nsP1 capping consists in the following reactions:
CC GTP is first methylated into 7-methyl-GMP and then is covalently linked
CC to nsP1 to form the m7GMp-nsP1 complex from which 7-methyl-GMP complex
CC is transferred to the mRNA to create the cap structure (By similarity).
CC NsP1 is needed for the initiation of the minus-strand RNAs synthesis
CC (By similarity). Probably serves as a membrane anchor for the
CC replication complex composed of nsP1-nsP4 (By similarity).
CC Palmitoylated nsP1 is remodeling host cell cytoskeleton, and induces
CC filopodium-like structure formation at the surface of the host cell (By
CC similarity). {ECO:0000250|UniProtKB:P03317,
CC ECO:0000250|UniProtKB:P08411, ECO:0000250|UniProtKB:Q8JUX6,
CC ECO:0000305}.
CC -!- FUNCTION: [Protease nsP2]: Multifunctional protein whose N-terminus is
CC part of the RNA polymerase complex and displays NTPase, RNA
CC triphosphatase and helicase activities (By similarity). NTPase and RNA
CC triphosphatase are involved in viral RNA capping and helicase keeps a
CC check on the dsRNA replication intermediates (By similarity). The C-
CC terminus harbors a protease that specifically cleaves the polyproteins
CC and releases the mature proteins (By similarity). Required for the
CC shutoff of minus-strand RNAs synthesis (By similarity). Specifically
CC inhibits the host IFN response by promoting the nuclear export of host
CC STAT1 (By similarity). Also inhibits host transcription by inducing
CC rapid proteasome-dependent degradation of POLR2A, a catalytic subunit
CC of the RNAPII complex (By similarity). The resulting inhibition of
CC cellular protein synthesis serves to ensure maximal viral gene
CC expression and to evade host immune response (By similarity).
CC {ECO:0000250|UniProtKB:P03317, ECO:0000250|UniProtKB:P08411,
CC ECO:0000250|UniProtKB:Q8JUX6}.
CC -!- FUNCTION: [Non-structural protein 3']: Seems to be essential for minus-
CC strand RNAs and subgenomic 26S mRNAs synthesis (By similarity).
CC Displays mono-ADP-ribosylhydrolase activity (Probable). ADP-
CC ribosylation is a post-translational modification that controls various
CC processes of the host cell and the virus probably needs to revert it
CC for optimal viral replication (Probable). Binds proteins of FXR family
CC and sequesters them into the viral RNA replication complexes thereby
CC inhibiting the formation of host stress granules on viral mRNAs
CC (Probable). The nsp3'-FXR complexes bind viral RNAs and probably
CC orchestrate the assembly of viral replication complexes, thanks to the
CC ability of FXR family members to self-assemble and bind DNA (Probable).
CC {ECO:0000250|UniProtKB:P03317, ECO:0000305}.
CC -!- FUNCTION: [Non-structural protein 3]: Seems to be essential for minus-
CC strand RNAs and subgenomic 26S mRNAs synthesis (By similarity).
CC Displays mono-ADP-ribosylhydrolase activity (By similarity). ADP-
CC ribosylation is a post-translantional modification that controls
CC various processes of the host cell and the virus probably needs to
CC revert it for optimal viral replication (By similarity). Binds proteins
CC of G3BP family and sequesters them into the viral RNA replication
CC complexes thereby inhibiting the formation of host stress granules on
CC viral mRNAs (By similarity). The nsp3-G3BP complexes bind viral RNAs
CC and probably orchestrate the assembly of viral replication complexes,
CC thanks to the ability of G3BP family members to self-assemble and bind
CC DNA (By similarity). {ECO:0000250|UniProtKB:P03317,
CC ECO:0000250|UniProtKB:Q8JUX6}.
CC -!- FUNCTION: [RNA-directed RNA polymerase nsP4]: RNA dependent RNA
CC polymerase (By similarity). Replicates genomic and antigenomic RNA by
CC recognizing replications specific signals. The early replication
CC complex formed by the polyprotein P123 and nsP4 synthesizes minus-
CC strand RNAs (By similarity). The late replication complex composed of
CC fully processed nsP1-nsP4 is responsible for the production of genomic
CC and subgenomic plus-strand RNAs (By similarity). The core catalytic
CC domain of nsP4 also possesses terminal adenylyltransferase (TATase)
CC activity that is probably involved in maintenance and repair of the
CC poly(A) tail, an element required for replication of the viral genome
CC (By similarity). {ECO:0000250|UniProtKB:P03317}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=GTP + S-adenosyl-L-methionine = N(7)-methyl-GTP + S-adenosyl-
CC L-homocysteine; Xref=Rhea:RHEA:46948, ChEBI:CHEBI:37565,
CC ChEBI:CHEBI:57856, ChEBI:CHEBI:59789, ChEBI:CHEBI:87133;
CC Evidence={ECO:0000250|UniProtKB:P27282};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=[nsP1 protein]-L-histidine + N(7)-methyl-GTP = [nsP1 protein]-
CC N(tele)-(N(7)-methylguanosine 5'-phospho)-L-histidine + diphosphate;
CC Xref=Rhea:RHEA:54792, Rhea:RHEA-COMP:13994, Rhea:RHEA-COMP:13995,
CC ChEBI:CHEBI:29979, ChEBI:CHEBI:33019, ChEBI:CHEBI:87133,
CC ChEBI:CHEBI:138334; Evidence={ECO:0000250|UniProtKB:P03317};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:54793;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=[nsP1 protein]-N(tele)-(N(7)-methylguanosine 5'-phospho)-L-
CC histidine + a 5'-end diphospho-(purine-ribonucleoside) in mRNA + H(+)
CC = [nsP1 protein]-L-histidine + a 5'-end (N(7)-methyl 5'-
CC triphosphoguanosine)-(purine-ribonucleoside) in mRNA;
CC Xref=Rhea:RHEA:54800, Rhea:RHEA-COMP:12925, Rhea:RHEA-COMP:13929,
CC Rhea:RHEA-COMP:13994, Rhea:RHEA-COMP:13995, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:29979, ChEBI:CHEBI:133968, ChEBI:CHEBI:138276,
CC ChEBI:CHEBI:138334; Evidence={ECO:0000250|UniProtKB:P27282};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a 5'-end triphospho-(purine-ribonucleoside) in mRNA + H2O = a
CC 5'-end diphospho-(purine-ribonucleoside) in mRNA + H(+) + phosphate;
CC Xref=Rhea:RHEA:11008, Rhea:RHEA-COMP:13929, Rhea:RHEA-COMP:13942,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:43474,
CC ChEBI:CHEBI:138276, ChEBI:CHEBI:138288; EC=3.1.3.33;
CC Evidence={ECO:0000250|UniProtKB:P08411};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a ribonucleoside 5'-triphosphate + H2O = a ribonucleoside 5'-
CC diphosphate + H(+) + phosphate; Xref=Rhea:RHEA:23680,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:43474,
CC ChEBI:CHEBI:57930, ChEBI:CHEBI:61557; EC=3.6.1.15;
CC Evidence={ECO:0000250|UniProtKB:Q8JUX6};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + H2O = ADP + H(+) + phosphate; Xref=Rhea:RHEA:13065,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616,
CC ChEBI:CHEBI:43474, ChEBI:CHEBI:456216; EC=3.6.4.13;
CC Evidence={ECO:0000250|UniProtKB:Q8JUX6};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate +
CC RNA(n+1); Xref=Rhea:RHEA:21248, Rhea:RHEA-COMP:14527, Rhea:RHEA-
CC COMP:17342, ChEBI:CHEBI:33019, ChEBI:CHEBI:61557, ChEBI:CHEBI:140395;
CC EC=2.7.7.48; Evidence={ECO:0000255|PROSITE-ProRule:PRU00539};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + RNA(n) = diphosphate + RNA(n)-3'-adenine ribonucleotide;
CC Xref=Rhea:RHEA:11332, Rhea:RHEA-COMP:14527, Rhea:RHEA-COMP:17347,
CC ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:140395,
CC ChEBI:CHEBI:173115; EC=2.7.7.19;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=4-O-(ADP-D-ribosyl)-L-aspartyl-[protein] + H2O = ADP-D-ribose
CC + H(+) + L-aspartyl-[protein]; Xref=Rhea:RHEA:54428, Rhea:RHEA-
CC COMP:9867, Rhea:RHEA-COMP:13832, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:29961, ChEBI:CHEBI:57967,
CC ChEBI:CHEBI:138102; Evidence={ECO:0000250|UniProtKB:P03317};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:54429;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=5-O-(ADP-D-ribosyl)-L-glutamyl-[protein] + H2O = ADP-D-ribose
CC + H(+) + L-glutamyl-[protein]; Xref=Rhea:RHEA:58248, Rhea:RHEA-
CC COMP:10208, Rhea:RHEA-COMP:15089, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:29973, ChEBI:CHEBI:57967,
CC ChEBI:CHEBI:142540; Evidence={ECO:0000250|UniProtKB:P03317};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:58249;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ADP-beta-D-ribose 1''-phosphate + H2O = ADP-D-ribose +
CC phosphate; Xref=Rhea:RHEA:25029, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:43474, ChEBI:CHEBI:57967, ChEBI:CHEBI:58753; EC=3.1.3.84;
CC Evidence={ECO:0000250|UniProtKB:Q8JUX6};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:25030;
CC Evidence={ECO:0000250|UniProtKB:Q8JUX6};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC Name=Mn(2+); Xref=ChEBI:CHEBI:29035;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC Note=For nsP4 adenylyltransferase activity; Mn(2+) supports catalysis
CC at 60% of the levels observed with Mg(2+).
CC {ECO:0000250|UniProtKB:P03317};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P03317};
CC Note=For nsP4 RNA-directed RNA polymerase activity.
CC {ECO:0000250|UniProtKB:P03317};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P27282};
CC Note=For nsP1 guanylylation. {ECO:0000250|UniProtKB:P27282};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Note=For nsP2 RNA triphosphatase activity.
CC {ECO:0000250|UniProtKB:Q8JUX6};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Note=For nsP2 NTPase activity. {ECO:0000250|UniProtKB:Q8JUX6};
CC -!- SUBUNIT: [mRNA-capping enzyme nsP1]: Interacts with non-structural
CC protein 3 (By similarity). Interacts with RNA-directed RNA polymerase
CC nsP4 (By similarity). Interacts with protease nsP2 (By similarity).
CC interacts with itself (By similarity). {ECO:0000250|UniProtKB:P03317,
CC ECO:0000250|UniProtKB:P27282}.
CC -!- SUBUNIT: [Non-structural protein 3]: Interacts with mRNA-capping enzyme
CC nsP1 (By similarity). Interacts with host DDX1 (By similarity).
CC Interacts with host DDX3 (By similarity). Interacts (via C-terminus)
CC with host G3BP1; this interaction inhibits the formation of host stress
CC granules on viral mRNAs and the nsp3-G3BP1 complexes bind viral RNAs
CC and probably orchestrate the assembly of viral replication complexes
CC (By similarity). Interacts (via C-terminus) with host G3BP2; this
CC interaction inhibits the formation of host stress granules on viral
CC mRNAs and the nsp3-G3BP2 complexes bind viral RNAs and probably
CC orchestrate the assembly of viral replication complexes (By
CC similarity). {ECO:0000250|UniProtKB:P03317,
CC ECO:0000250|UniProtKB:P27282}.
CC -!- SUBUNIT: [RNA-directed RNA polymerase nsP4]: Interacts with mRNA-
CC capping enzyme nsP1 (By similarity). Interacts with protease nsP2 (By
CC similarity). interacts with itself (By similarity).
CC {ECO:0000250|UniProtKB:P03317, ECO:0000250|UniProtKB:P27282}.
CC -!- SUBUNIT: [Protease nsP2]: Interacts with RNA-directed RNA polymerase
CC nsP4 (By similarity). Interacts with mRNA-capping enzyme nsP1 (By
CC similarity). Interacts with KPNA1/karyopherin-alpha1; this interaction
CC probably allows the active transport of protease nsP2 into the host
CC nucleus (By similarity). {ECO:0000250|UniProtKB:P03317,
CC ECO:0000250|UniProtKB:P27282}.
CC -!- SUBCELLULAR LOCATION: [Polyprotein P1234]: Host cytoplasmic vesicle
CC membrane {ECO:0000305}; Peripheral membrane protein {ECO:0000305}.
CC Note=Part of cytoplasmic vesicles, which are probably formed at the
CC plasma membrane and internalized leading to late endosomal/lysosomal
CC spherules containing the replication complex. {ECO:0000305}.
CC -!- SUBCELLULAR LOCATION: [Polyprotein P123']: Host cytoplasmic vesicle
CC membrane {ECO:0000305}; Peripheral membrane protein {ECO:0000305}.
CC Note=Part of cytoplasmic vesicles, which are probably formed at the
CC plasma membrane and internalized leading to late endosomal/lysosomal
CC spherules containing the replication complex. {ECO:0000305}.
CC -!- SUBCELLULAR LOCATION: [Polyprotein P123]: Host cytoplasmic vesicle
CC membrane {ECO:0000305}; Peripheral membrane protein {ECO:0000305}.
CC Note=Part of cytoplasmic vesicles, which are probably formed at the
CC plasma membrane and internalized leading to late endosomal/lysosomal
CC spherules containing the replication complex. {ECO:0000305}.
CC -!- SUBCELLULAR LOCATION: [mRNA-capping enzyme nsP1]: Host cytoplasmic
CC vesicle membrane {ECO:0000250|UniProtKB:P08411}; Lipid-anchor
CC {ECO:0000250|UniProtKB:P08411}. Host cell membrane
CC {ECO:0000250|UniProtKB:P08411}; Lipid-anchor
CC {ECO:0000250|UniProtKB:P08411}; Cytoplasmic side
CC {ECO:0000250|UniProtKB:P08411}. Host cell projection, host filopodium
CC {ECO:0000250|UniProtKB:P08411}. Note=In the late phase of infection,
CC the polyprotein is quickly cleaved before localization to cellular
CC membranes. Then a fraction of nsP1 localizes to the inner surface of
CC the plasma membrane and its filopodial extensions. Only the
CC palmitoylated nsP1 localizes to the host filopodia (By similarity).
CC NsP1 is also part of cytoplasmic vesicles, which are probably formed at
CC the plasma membrane and internalized leading to late
CC endosomal/lysosomal spherules containing the replication complex (By
CC similarity). {ECO:0000250|UniProtKB:P08411}.
CC -!- SUBCELLULAR LOCATION: [Protease nsP2]: Host cytoplasmic vesicle
CC membrane {ECO:0000250|UniProtKB:P08411}; Peripheral membrane protein
CC {ECO:0000250|UniProtKB:P08411}. Host nucleus
CC {ECO:0000250|UniProtKB:P27282}. Host cytoplasm
CC {ECO:0000250|UniProtKB:P27282}. Note=In the late phase of infection,
CC the polyprotein is quickly cleaved before localization to cellular
CC membranes. Then approximately half of nsP2 is found in the nucleus (By
CC similarity). Shuttles between cytoplasm and nucleus (By similarity).
CC NsP2 is also part of cytoplasmic vesicles, which are probably formed at
CC the plasma membrane and internalized leading to late
CC endosomal/lysosomal spherules containing the replication complex (By
CC similarity). {ECO:0000250|UniProtKB:P08411,
CC ECO:0000250|UniProtKB:P27282}.
CC -!- SUBCELLULAR LOCATION: [Non-structural protein 3']: Host cytoplasmic
CC vesicle membrane {ECO:0000250|UniProtKB:P03317}; Peripheral membrane
CC protein {ECO:0000305}. Note=In the late phase of infection, the
CC polyprotein is quickly cleaved before localization to cellular
CC membranes. Then nsP3 and nsP3' form aggregates in cytoplasm (By
CC similarity). NsP3' is also part of cytoplasmic vesicles, which are
CC probably formed at the plasma membrane and internalized leading to late
CC endosomal/lysosomal spherules containing the replication complex (By
CC similarity). {ECO:0000250|UniProtKB:P03317}.
CC -!- SUBCELLULAR LOCATION: [Non-structural protein 3]: Host cytoplasmic
CC vesicle membrane {ECO:0000250|UniProtKB:P03317}; Peripheral membrane
CC protein {ECO:0000305}. Note=In the late phase of infection, the
CC polyprotein is quickly cleaved before localization to cellular
CC membranes. Then nsP3 and nsP3' form aggregates in cytoplasm (By
CC similarity). NsP3 is also part of cytoplasmic vesicles, which are
CC probably formed at the plasma membrane and internalized leading to late
CC endosomal/lysosomal spherules containing the replication complex (By
CC similarity). {ECO:0000250|UniProtKB:P03317}.
CC -!- SUBCELLULAR LOCATION: [RNA-directed RNA polymerase nsP4]: Host
CC cytoplasmic vesicle membrane; Peripheral membrane protein
CC {ECO:0000250|UniProtKB:P03317}. Note=NsP4 is part of cytoplasmic
CC vesicles, which are probably formed at the plasma membrane and
CC internalized leading to late endosomal/lysosomal spherules containing
CC the replication complex. {ECO:0000250|UniProtKB:P08411}.
CC -!- DOMAIN: [Protease nsP2]: The N-terminus exhibits NTPase and RNA
CC triphosphatase activities and is proposed to have helicase activity,
CC whereas the C-terminus possesses protease activity (By similarity).
CC Contains a nuclear localization signal and a nuclear export signal,
CC these two motifs are probably involved in the shuttling between the
CC cytoplasm and the nucleus of nsP2 (By similarity). The C-terminus is
CC required for promoting the export of host STAT1 (By similarity).
CC {ECO:0000250|UniProtKB:P27282, ECO:0000250|UniProtKB:Q8JUX6}.
CC -!- DOMAIN: [Non-structural protein 3]: In the N-terminus, the macro domain
CC displays a mono-ADP-ribosylhydrolase activity (By similarity). The
CC central part has a zinc-binding function (By similarity). The C-
CC terminus contains two FGDF motifs necessary and sufficient for
CC formation of the nsP3/G3BP1 complex (By similarity).
CC {ECO:0000250|UniProtKB:P03317, ECO:0000250|UniProtKB:P08411}.
CC -!- DOMAIN: [Non-structural protein 3']: In the N-terminus, the macro
CC domain displays a mono-ADP-ribosylhydrolase activity (By similarity).
CC The central part has a zinc-binding function (By similarity). The C-
CC terminus contains two FGDF motifs necessary and sufficient for
CC formation of the nsP3'/G3BP1 complex (By similarity).
CC {ECO:0000250|UniProtKB:P03317, ECO:0000250|UniProtKB:P08411}.
CC -!- PTM: [Polyprotein P1234]: Specific enzymatic cleavages in vivo yield
CC mature proteins (By similarity). The processing of the polyprotein is
CC temporally regulated (By similarity). In early stages (1.7 hpi), P1234
CC is first cleaved in trans through its nsP2 protease activity, releasing
CC P123' and nsP4, which associate to form the early replication complex
CC (By similarity). At the same time, P1234 is also cut at the nsP1/nsP2
CC site early in infection but with lower efficiency (By similarity).
CC After replication of the viral minus-strand RNAs (4 hpi), the
CC polyproteins are cut at the nsP1/nsP2 and nsP2/nsP3 sites very
CC efficiently, preventing accumulation of P123' and P1234 and allowing
CC the formation of the late replication complex (By similarity).
CC NsP3'/nsP4 site is not cleaved anymore and P34 is produced rather than
CC nsP4 (By similarity). {ECO:0000250|UniProtKB:P03317}.
CC -!- PTM: [Polyprotein P123]: Specific enzymatic cleavages in vivo yield
CC mature proteins (By similarity). The processing of the polyprotein is
CC temporally regulated (By similarity). In early stages (1.7 hpi), P123
CC is cleaved at the nsP1/nsP2 site with low efficiency (By similarity).
CC After replication of the viral minus-strand RNAs (4 hpi), the
CC polyproteins are cut at the nsP1/nsP2 and nsP2/nsP3 sites very
CC efficiently, preventing accumulation of P123 and allowing the formation
CC of the late replication complex (By similarity).
CC {ECO:0000250|UniProtKB:P03317}.
CC -!- PTM: [Polyprotein P123']: Specific enzymatic cleavages in vivo yield
CC mature proteins (By similarity). The processing of the polyprotein is
CC temporally regulated (By similarity). In early stages (1.7 hpi), P123'
CC is cleaved at the nsP1/nsP2 site with low efficiency (By similarity).
CC After replication of the viral minus-strand RNAs (4 hpi), the
CC polyproteins are cut at the nsP1/nsP2 and nsP2/nsP3 sites very
CC efficiently, preventing accumulation of P123' and allowing the
CC formation of the late replication complex (By similarity).
CC {ECO:0000250|UniProtKB:P03317}.
CC -!- PTM: [mRNA-capping enzyme nsP1]: Palmitoylated by host
CC palmitoyltransferases ZDHHC2 and ZDHHC19.
CC {ECO:0000250|UniProtKB:Q8JUX6}.
CC -!- PTM: [Non-structural protein 3]: Phosphorylated by host on serines and
CC threonines. {ECO:0000250|UniProtKB:P08411}.
CC -!- PTM: [Non-structural protein 3']: Phosphorylated by host on serines and
CC threonines. {ECO:0000250|UniProtKB:P08411}.
CC -!- PTM: [RNA-directed RNA polymerase nsP4]: Ubiquitinated; targets the
CC protein for rapid degradation via the ubiquitin system (By similarity).
CC Nsp4 is present in extremely low quantities due to low frequency of
CC translation through the amber stop-codon and the degradation by the
CC ubiquitin pathway (By similarity). {ECO:0000250|UniProtKB:P03317}.
CC -!- MISCELLANEOUS: Viral replication produces dsRNA in the late phase of
CC infection, resulting in a strong activation of host EIF2AK2/PKR,
CC leading to almost complete phosphorylation of EIF2A (By similarity).
CC This inactivates completely cellular translation initiation, resulting
CC shutoff of host proteins synthesis (By similarity). However,
CC phosphorylation of EIF2A is probably not the only mechanism responsible
CC for the host translation shutoff (By similarity). The viral translation
CC can still occur normally because it relies on a hairpin structure in
CC the coding region of sgRNA and is EIF2A-, EIF2D-, EIF4G- EIF4A-
CC independent (By similarity). {ECO:0000250|UniProtKB:P03317}.
CC -!- MISCELLANEOUS: The genome codes for P123, but readthrough of a
CC terminator codon UGA occurs between the codons for Tyr-1898 and Leu-
CC 1900 giving rise to P1234 (Probable). P1234 is cleaved quickly by nsP2
CC into P123' and nsP4 (By similarity). Further processing of p123' gives
CC nsP1, nsP2 and nsP3' which is 6 amino acids longer than nsP3 since the
CC cleavage site is after the readthrough (By similarity). This unusual
CC molecular mechanism ensures that few nsP4 are produced compared to
CC other non-structural proteins (By similarity). Mutant viruses with no
CC alternative termination site grow significantly slower than wild-type
CC virus (By similarity). The opal termination codon is frequently mutated
CC to a sense codon on passage in cell culture (By similarity). The
CC presence of the opal codon may be a requirement for viral maintenance
CC in both vertebrate and invertebrate hosts and a selective advantage may
CC be conferred in cell culture for the sense codon (By similarity).
CC {ECO:0000250|UniProtKB:O90368, ECO:0000250|UniProtKB:P03317,
CC ECO:0000305}.
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DR EMBL; M69205; AAA96972.1; ALT_SEQ; Genomic_RNA.
DR PIR; A39991; MNWV82.
DR MEROPS; C09.001; -.
DR Proteomes; UP000006561; Genome.
DR GO; GO:0044162; C:host cell cytoplasmic vesicle membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0044176; C:host cell filopodium; IEA:UniProtKB-SubCell.
DR GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR GO; GO:0016887; F:ATP hydrolysis activity; IEA:RHEA.
DR GO; GO:0008234; F:cysteine-type peptidase activity; IEA:UniProtKB-KW.
DR GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008174; F:mRNA methyltransferase activity; IEA:InterPro.
DR GO; GO:0004651; F:polynucleotide 5'-phosphatase activity; IEA:UniProtKB-EC.
DR GO; GO:0004652; F:polynucleotide adenylyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR GO; GO:0003724; F:RNA helicase activity; IEA:UniProtKB-EC.
DR GO; GO:0003968; F:RNA-directed 5'-3' RNA polymerase activity; IEA:UniProtKB-KW.
DR GO; GO:0006370; P:7-methylguanosine mRNA capping; IEA:UniProtKB-KW.
DR GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR GO; GO:0039523; P:suppression by virus of host mRNA transcription via inhibition of RNA polymerase II activity; IEA:UniProtKB-KW.
DR GO; GO:0006351; P:transcription, DNA-templated; IEA:InterPro.
DR GO; GO:0039694; P:viral RNA genome replication; IEA:InterPro.
DR CDD; cd21557; Macro_X_Nsp3-like; 1.
DR Gene3D; 3.40.220.10; -; 1.
DR Gene3D; 3.40.50.150; -; 1.
DR Gene3D; 3.40.50.300; -; 2.
DR Gene3D; 3.90.70.110; -; 1.
DR InterPro; IPR027351; (+)RNA_virus_helicase_core_dom.
DR InterPro; IPR002588; Alphavirus-like_MT_dom.
DR InterPro; IPR002620; Alphavirus_nsp2pro.
DR InterPro; IPR044936; Alphavirus_nsp2pro_sf.
DR InterPro; IPR043502; DNA/RNA_pol_sf.
DR InterPro; IPR002589; Macro_dom.
DR InterPro; IPR043472; Macro_dom-like.
DR InterPro; IPR044371; Macro_X_NSP3-like.
DR InterPro; IPR027417; P-loop_NTPase.
DR InterPro; IPR007094; RNA-dir_pol_PSvirus.
DR InterPro; IPR029063; SAM-dependent_MTases_sf.
DR InterPro; IPR001788; Tymovirus_RNA-dep_RNA_pol.
DR Pfam; PF01661; Macro; 1.
DR Pfam; PF01707; Peptidase_C9; 1.
DR Pfam; PF00978; RdRP_2; 1.
DR Pfam; PF01443; Viral_helicase1; 1.
DR Pfam; PF01660; Vmethyltransf; 1.
DR SMART; SM00506; A1pp; 1.
DR SUPFAM; SSF52540; SSF52540; 1.
DR SUPFAM; SSF52949; SSF52949; 1.
DR SUPFAM; SSF53335; SSF53335; 1.
DR SUPFAM; SSF56672; SSF56672; 1.
DR PROSITE; PS51743; ALPHAVIRUS_MT; 1.
DR PROSITE; PS51154; MACRO; 1.
DR PROSITE; PS51520; NSP2PRO; 1.
DR PROSITE; PS51657; PSRV_HELICASE; 1.
DR PROSITE; PS50507; RDRP_SSRNA_POS; 1.
PE 3: Inferred from homology;
KW ATP-binding; Eukaryotic host gene expression shutoff by virus;
KW Eukaryotic host transcription shutoff by virus; GTP-binding; Helicase;
KW Host cell membrane; Host cell projection; Host cytoplasm;
KW Host cytoplasmic vesicle; Host gene expression shutoff by virus;
KW Host membrane; Host nucleus; Host-virus interaction; Hydrolase;
KW Inhibition of host RNA polymerase II by virus; Lipoprotein; Membrane;
KW Metal-binding; Methyltransferase; mRNA capping; mRNA processing;
KW Multifunctional enzyme; Nucleotide-binding; Nucleotidyltransferase;
KW Palmitate; Phosphoprotein; Protease; RNA suppression of termination;
KW RNA-binding; RNA-directed RNA polymerase; S-adenosyl-L-methionine;
KW Thiol protease; Transferase; Ubl conjugation; Viral RNA replication; Zinc.
FT CHAIN 1..2515
FT /note="Polyprotein P1234"
FT /id="PRO_0000308404"
FT CHAIN 1..1905
FT /note="Polyprotein P123'"
FT /id="PRO_0000228788"
FT CHAIN 1..1898
FT /note="Polyprotein P123"
FT /id="PRO_0000228789"
FT CHAIN 1..540
FT /note="mRNA-capping enzyme nsP1"
FT /id="PRO_0000041232"
FT CHAIN 541..1347
FT /note="Protease nsP2"
FT /id="PRO_0000041233"
FT CHAIN 1348..1905
FT /note="Non-structural protein 3'"
FT /id="PRO_0000228790"
FT CHAIN 1348..1898
FT /note="Non-structural protein 3"
FT /id="PRO_0000041234"
FT CHAIN 1906..2515
FT /note="RNA-directed RNA polymerase nsP4"
FT /id="PRO_0000041235"
FT DOMAIN 30..260
FT /note="Alphavirus-like MT"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01079"
FT DOMAIN 695..850
FT /note="(+)RNA virus helicase ATP-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00990"
FT DOMAIN 851..999
FT /note="(+)RNA virus helicase C-terminal"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00990"
FT DOMAIN 1012..1341
FT /note="Peptidase C9"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00853"
FT DOMAIN 1348..1507
FT /note="Macro"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00490"
FT DOMAIN 2269..2384
FT /note="RdRp catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00539"
FT REGION 245..264
FT /note="NsP1 membrane-binding"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT REGION 1013..1032
FT /note="Nucleolus localization signal"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT REGION 1677..1707
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 1777..1798
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOTIF 1066..1075
FT /note="Nuclear export signal"
FT /evidence="ECO:0000250|UniProtKB:P27282"
FT MOTIF 1196..1200
FT /note="Nuclear localization signal"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT MOTIF 1839..1842
FT /note="FGDF; binding to host G3BP1"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT MOTIF 1862..1865
FT /note="FGDF; binding to host G3BP1"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT ACT_SITE 1021
FT /note="For cysteine protease nsP2 activity"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00853"
FT ACT_SITE 1098
FT /note="For cysteine protease nsP2 activity"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00853"
FT BINDING 726..733
FT /ligand="a ribonucleoside 5'-triphosphate"
FT /ligand_id="ChEBI:CHEBI:61557"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00990"
FT BINDING 1371
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1379
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1459
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:P36328"
FT BINDING 1460
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:P36328"
FT BINDING 1461
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1610
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT BINDING 1612
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT BINDING 1635
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT BINDING 1653
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT SITE 39
FT /note="Involved in the phosphoramide link with 7-methyl-
FT GMP"
FT /evidence="ECO:0000250|UniProtKB:P27282"
FT SITE 540..541
FT /note="Cleavage; by protease nsP2"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT SITE 1347..1348
FT /note="Cleavage; by protease nsP2"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT SITE 1905..1906
FT /note="Cleavage; by protease nsP2"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT LIPID 420
FT /note="S-palmitoyl cysteine; by host"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
SQ SEQUENCE 2515 AA; 279756 MW; 6D1E32E092B05383 CRC64;
MEKPVVNVDV DPQSPFVVQL QKSFPQFEVV AQQATPNDHA NARAFSHLAS KLIELEVPTT
ATILDIGSAP ARRMFSEHQY HCVCPMRSPE DPDRMMKYAS KLAEKACKIT NKNLHEKIKD
LRTVLDTPDA ETPSLCFHND VTCNTRAEYS VMQDVYINAP GTIYHQAMKG VRTLYWIGFD
TTQFMFSAMA GSYPAYNTNW ADEKVLEARN IGLCSTKLSE GRTGKLSIMR KKELKPGSRV
YFSVGSTLYP EHRASLQSWH LPSVFHLKGK QSYTCRCDTV VSCEGYVVKK ITISPGITGE
TVGYAVTNNS EGFLLCKVTD TVKGERVSFP VCTYIPATIC DQMTGIMATD ISPDDAQKLL
VGLNQRIVIN GKTNRNTNTM QNYLLPTIAQ GFSKWAKERK EDLDNEKMLG TRERKLTYGC
LWAFRTKKVH SFYRPPGTQT SVKVPASFSA FPMSSVWTTS LPMSLRQKMK LALQPKKEEK
LLQVPEELVM EAKAAFEDAQ EEARAEKLRE ALPPLVADKD IEAAAEVVCE VEGLQADIGA
ALVETPRGHV RIIPQANDRM IGQYIVVSPT SVLKNAKLAP AHPLADQVKI ITHSGRAGRY
AVEPYDAKVL MPAGSAVPWP EFLALSESAT LVYNEREFVN RKLYHIAMHG PAKNTEEEQY
KVTKAELAET EYVFDVDKKR CVKKEEASGL VLSGELTNPP YHELALEGLK TRPAVPYKVE
TIGVIGTPGS GKSAIIKSTV TARDLVTSGK KENCREIEAD VLRLRGMQIT SKTVDSVMLN
GCHKAVEVLY VDEAFACHAG ALLALIAIVR PRKKVVLCGD PKQCGFFNMM QLKVHFNHPE
RDICTKTFYK FISRRCTQPV TAIVSTLHYD GKMKTTNPCK KNIEIDITGA TKPKPGDIIL
TCFRGWVKQL QIDYPGHEVM TAAASQGLTR KGVYAVRQKV NENALYAITS EHVNVLLTRT
EDRLVWKTLQ GDPWIKQLTN VPKGNFQATI EDWEAEHKGI IAAINSPAPR TNPFSCKTNV
CWAKALEPIL ATAGIVLTGC QWSELFPQFA DDKPHSAIYA LDVICIKFFG MDLTSGLFSK
QSIPLTYHPA DSARPVAHWD NSPGTRKYGY DHAVAAELSR RFPVFQLAGK GTQLDLQTGR
TRVISAQHNL VPVNRNLPHA LVPEHKEKQP GPVEKFLNQF KHHSVLVVSE EKIEAPHKRI
EWIAPIGIAG ADKNYNLAFG FPPQARYDLV FINIGTKYRN HHFQQCEDHA ATLKTLSRSA
LNCLNPGGTL VVKSYGYADR NSEDVVTALA RKFVRVSAAR PECVSSNTEM YLIFRQLDNS
RTRQFTPHHL NCVISSVYEG TRDGVGAAPS YRTKRENIAD CQEEAVVNAA NPLGRPGEGV
CRAIYKRWPN SFTDSATETG TAKLTVCHGK KVIHAVGPDF RKHPEAEALK LLQNAYHAVA
DLVNEHNIKS VAIPLLSTGI YAAGKDRLEV SLNCLTTALD RTDADVTIYC LDKKWKERID
AVLQLKESVT ELKDEDMEID DELVWIHPDS CLKGRKGFST TKGKLYSYFE GTKFHQAAKD
MAEIKVLFPN DQESNEQLCA YILGETMEAI REKCPVDHNP SSSPPKTLPC LCMYAMTPER
VHRLRSNNVK EVTVCSSTPL PKYKIKNVQK VQCTKVVLFN PHTPAFVPAR KYIEVPEQPA
APPAQDEEAP EAVATPAPPA ADNTSLDVTD ISLDMDDSSE GSLFSSFSGS DNSITCMDRW
SSGPSSLDRR QVVVADVHAV QEPAPIPPPR LKKMARLAAA SKTQEEPIPP ASTSSADESL
HLSFGGVSMS FGSLLDGEMA RLAAAQPPAT GPTDVPMSFG SFSDGEIEEL SRRVTESEPV
LFGSFEPGEV NSIISSRSAV SFPLRKQRRR RRSRRTEYXL TGVGGYIFST DTGPGHLQMK
SVLQNQLTEP TLERNVLERI YAPVLDTSKE EQLKLRYQMM PTEANKSRYQ SRKVENQKAI
TTERLLSGLR LYNSATDQPE CYKITYPKPS YSSSVAANYS DPKFAVAVCN NYLHENYPTV
ASYQITDEYD AYLDMVDGTV ACLDTATFCP AKLRSYPKRH EYRAPNIRSA VPSAMQNTLQ
NVLIAATKRN CNVTQMRELP TLDSATFNVE CFRKYACNDE YWEEFARKPI RITTEFVTAY
VARLKGPKAA ALFAKTHNLV PLQEVPMDRF VMDMKRDVKV TPGTKHTEER PKVQVIQAAE
PLATAYLCGI HRELVRRLTA VLLPNIHTLF DMSAEDFDAI IAEHFKQGDP VLETDIASFD
KSQDDAMALT GLMILEDLGV DQPLLDLIEC AFGEISSTHL PTGTRFKFGA MMKSGMFLTL
FVNTVLNVVI ASRVLEERLK TSKCAAFIGD DNIIHGVVSD KEMAERCATW LNMEVKIIDA
VIGERPPYFC GGFILQDSVT STACRVADPL KRLFKLGKPL PADDEQDEDR RRALLDETKA
WFRVGITDTL AVAVATRYEV DNITPVLLAL RTFAQSKRAF QAIRGEIKHL YGGPK
