POLN_ONNVS
ID POLN_ONNVS Reviewed; 2513 AA.
AC O90368;
DT 04-APR-2006, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1998, sequence version 1.
DT 03-AUG-2022, entry version 130.
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 O'nyong-nyong virus (strain SG650) (ONNV).
OC Viruses; Riboviria; Orthornavirae; Kitrinoviricota; Alsuviricetes;
OC Martellivirales; Togaviridae; Alphavirus.
OX NCBI_TaxID=374989;
OH NCBI_TaxID=44482; Anopheles.
OH NCBI_TaxID=9606; Homo sapiens (Human).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA], AND READTHROUGH.
RX PubMed=9875334; DOI=10.1006/viro.1998.9437;
RA Lanciotti R.S., Ludwig M.L., Rwaguma E.B., Lutwama J.J., Kram T.M.,
RA Karabatsos N., Cropp B.C., Miller B.R.;
RT "Emergence of epidemic O'nyong-nyong fever in Uganda after a 35-year
RT absence: genetic characterization of the virus.";
RL Virology 252:258-268(1998).
RN [2]
RP READTHROUGH.
RX PubMed=16641290; DOI=10.1128/jvi.80.10.4992-4997.2006;
RA Myles K.M., Kelly C.L., Ledermann J.P., Powers A.M.;
RT "Effects of an opal termination codon preceding the nsP4 gene sequence in
RT the O'Nyong-Nyong virus genome on Anopheles gambiae infectivity.";
RL J. Virol. 80:4992-4997(2006).
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
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: [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: [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 (Probable). nsP1 capping consists in the following reactions: GTP
CC is first methylated into 7-methyl-GMP and then is covalently linked to
CC nsP1 to form the m7GMp-nsP1 complex from which 7-methyl-GMP complex is
CC transferred to the mRNA to create the cap structure (By similarity).
CC NsP1 is also needed for the initiation of the minus-strand RNAs
CC synthesis (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:P27282,
CC ECO:0000250|UniProtKB:Q8JUX6, 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 the
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-translational modification that controls various
CC processes of the host cell and the virus probably needs to revert it
CC for optimal viral replication (By similarity). Binds proteins of G3BP
CC family and sequesters them into the viral RNA replication complexes
CC thereby inhibiting the formation of host stress granules on viral mRNAs
CC (By similarity). The nsp3-G3BP complexes bind viral RNAs and probably
CC orchestrate the assembly of viral replication complexes, thanks to the
CC ability of G3BP family members to self-assemble and bind DNA (By
CC 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).
CC {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:P27282};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:54793;
CC Evidence={ECO:0000250|UniProtKB:P27282};
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=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:Q8JUX6};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:54429;
CC Evidence={ECO:0000250|UniProtKB:Q8JUX6};
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:Q8JUX6};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:58249;
CC Evidence={ECO:0000250|UniProtKB:Q8JUX6};
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=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 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, ECO:0000250|UniProtKB:Q8JUX6}.
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, ECO:0000250|UniProtKB:Q8JUX6}.
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 ECO:0000250|UniProtKB:Q8JUX6}.
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, ECO:0000250|UniProtKB:Q8JUX6}.
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: [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:Q8JUX6}. 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 ECO:0000250|UniProtKB:Q8JUX6}.
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:P08411}. 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:Q8JUX6}.
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:Q8JUX6}.
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 Leu-1895 and Leu-
CC 1897 (PubMed:9875334). This readthrough produces P1234, cleaved quickly
CC by nsP2 into P123' and nsP4 (PubMed:9875334). Further processing of
CC p123' gives nsP1, nsP2 and nsP3' which is 6 amino acids longer than
CC nsP3 since the cleavage site is after the readthrough (PubMed:9875334).
CC This unusual molecular mechanism ensures that few nsP4 are produced
CC compared to other non-structural proteins (PubMed:9875334). Mutant
CC viruses with no alternative termination site grow significantly slower
CC than wild-type virus (By similarity). The opal termination codon is
CC frequently mutated to a sense codon on passage in cell culture
CC (PubMed:9875334). The presence of the opal codon may be a requirement
CC for viral maintenance in both vertebrate and invertebrate hosts and a
CC selective advantage may be conferred in cell culture for the sense
CC codon (PubMed:9875334, PubMed:16641290). {ECO:0000250|UniProtKB:P03317,
CC ECO:0000269|PubMed:16641290, ECO:0000269|PubMed:9875334}.
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DR EMBL; AF079456; AAC97204.1; -; Genomic_RNA.
DR MEROPS; C09.001; -.
DR PRIDE; O90368; -.
DR Proteomes; UP000007787; 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; 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..2513
FT /note="Polyprotein P1234"
FT /id="PRO_0000308399"
FT CHAIN 1..1902
FT /note="Polyprotein P123'"
FT /id="PRO_0000229938"
FT CHAIN 1..1895
FT /note="Polyprotein P123"
FT /id="PRO_0000446650"
FT CHAIN 1..535
FT /note="mRNA-capping enzyme nsP1"
FT /id="PRO_0000229939"
FT CHAIN 536..1333
FT /note="Protease nsP2"
FT /id="PRO_0000229940"
FT CHAIN 1334..1902
FT /note="Non-structural protein 3'"
FT /id="PRO_0000229941"
FT CHAIN 1334..1895
FT /note="Non-structural protein 3"
FT /id="PRO_0000446651"
FT CHAIN 1903..2513
FT /note="RNA-directed RNA polymerase nsP4"
FT /id="PRO_0000229942"
FT DOMAIN 28..259
FT /note="Alphavirus-like MT"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01079"
FT DOMAIN 690..842
FT /note="(+)RNA virus helicase ATP-binding"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00990"
FT DOMAIN 843..991
FT /note="(+)RNA virus helicase C-terminal"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00990"
FT DOMAIN 1004..1327
FT /note="Peptidase C9"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00853"
FT DOMAIN 2267..2382
FT /note="RdRp catalytic"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00539"
FT REGION 244..263
FT /note="NsP1 membrane-binding"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT REGION 1005..1024
FT /note="Nucleolus localization signal"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT MOTIF 1058..1067
FT /note="Nuclear export signal"
FT /evidence="ECO:0000250|UniProtKB:P27282"
FT MOTIF 1182..1186
FT /note="Nuclear localization signal"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT MOTIF 1851..1854
FT /note="FGDF; binding to host G3BP1"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT MOTIF 1869..1872
FT /note="FGDF; binding to host G3BP1"
FT /evidence="ECO:0000250|UniProtKB:P08411"
FT ACT_SITE 1013
FT /note="For cysteine protease nsP2 activity"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00853"
FT ACT_SITE 1083
FT /note="For cysteine protease nsP2 activity"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00853"
FT BINDING 721..728
FT /ligand="a ribonucleoside 5'-triphosphate"
FT /ligand_id="ChEBI:CHEBI:61557"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00990"
FT BINDING 1343
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:P36328"
FT BINDING 1357
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1365
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1445
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:P36328"
FT BINDING 1446
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1447
FT /ligand="ADP-D-ribose"
FT /ligand_id="ChEBI:CHEBI:57967"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT BINDING 1595
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT BINDING 1597
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT BINDING 1620
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT BINDING 1638
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT SITE 37
FT /note="Involved in the phosphoramide link with 7-methyl-
FT GMP"
FT /evidence="ECO:0000250|UniProtKB:P27282"
FT SITE 535..536
FT /note="Cleavage; by protease nsP2"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT SITE 1333..1334
FT /note="Cleavage; by protease nsP2"
FT /evidence="ECO:0000250|UniProtKB:P03317"
FT SITE 1902..1903
FT /note="Cleavage; by protease nsP2"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT LIPID 417
FT /note="S-palmitoyl cysteine; by host"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
FT LIPID 419
FT /note="S-palmitoyl cysteine; by host"
FT /evidence="ECO:0000250|UniProtKB:Q8JUX6"
SQ SEQUENCE 2513 AA; 280222 MW; 1B546AD981E5F2A7 CRC64;
MDSVYVDIDA DSAFLKALQR AYPMFEVEPK QVTPNDHANA RAFSHLAIKL IEQEIDPDST
ILDIGPAPAR RMMSDRKYHC VCPMRSAEDP ERLANYARKL ASAAGKVTDK NISGKINDLQ
AVMAVPNMET STFCLHTDAT CKQRGDVAIY QDVYAVHAPT SLYHQAIKGV RVAYWIGFDT
TPFMYNAMAG AYPSYSTNWA DEQVLKAKNI GLCSTDLSEG RRGKLSIMRG KKLKPCDRVL
FSVGSTLYPE SRKLLQSWHL PSVFHLKGKL SFTCRCDTIV SCEGYVVKRV TMSPGIYGKT
SGYAVTHHAD GFLMCKTTDT VDGERVSFSV CTYVPATICD QMTGILATEV TPEDAQKLLV
GLNQRIVVNG RTQRNTNTMK NYLLPIVAQA FSKWAKECRK DMEDEKLLGV RERTLTCCCL
WAFRKHKTHT VYKRPDTQSI QKVPAEFDSF VIPSLWSSGL SIPLRTRIKW LLSKAPKHEQ
LPHSGNAEEA AQAEMDAAEE REAELTREAM PPLQATQDDV QVEIDVEQLE DRAGAGIVET
PRGAIKVTAQ PSDRVVGEYL VLTPQAVLRS QKLSLIHALA EQVKTCTHSG RAGRYAVEAY
DGRVLVPSGY AIPQEDFQSL SESATMVFNE REFVNRKLHH IAMHGPALNT DEESYELVRV
EKTEHEYVYD VDQKKCCKRE EATGLVLVGD LTSPPYHEFA YEGLKIRPAC PYKTAVIGVF
GVPGSGKSAI IKNLVTRQDL VTSGKKENCQ EISNDVMRQR KLEISARTVD SLLLNGCNKP
VEVLYVDEAF ACHSGTLLAL IAMVRPRQKV VLCGDPKQCG FFNMMQMKVN YNHNICTQVY
HKSISRRCTL PVTAIVSSLH YESKMRTTNE YNQPIVVDTT GITKPEPGDL VLTCFRGWVK
QLQIDYRGNE VMTAAASQGL TRKGVYAVRQ KVNENPLYAS TSEHVNVLLT RTEGKLIWKT
LSGDPWIKIL QNPPKGNFKA TIKEWEAEHA SIMAGICNHQ MAFDTFQNKA NVCWAKCLVP
ILDTAGIKLS DRQWSQIVQA FKEDRAYSPE VALNEICTRI YGVDLDSGLF SKPLISVYYA
DNHWDNRPGG KMFGFNPEVA LMLEKKYPFT KGKWNINKQI CITTRKVDEF NPETNIIPAN
RRLPHSLVAE HHTVRGERME WLVNKINGHH MLLVSGYNLI LPTKRVTWVA PLGTRGADYT
YNLELGLPAT LGRYDLVVIN IHTPFRIHHY QQCVDHAMKL QMLGGDSLRL LKPGGSLLIR
AYGYADRTSE RVISVLGRKF RSSRALKPQC ITSNTEMFFL FSRFDNGRRN FTTHVMNNQL
NAVYAGLATR AGCAPSYRVK RMDIAKNTEE CVVNAANPRG VPGDGVCKAV YRKWPESFRN
SATPVGTAKT IMCGQYPVIH AVGPNFSNYS EAEGDRELAS VYREVAKEVS RLGVSSVAIP
LLSTGVYSGG KDRLLQSLNH LFTAMDSTDA DVVIYCRDKE WEKKITEAIS LRSQVELLDD
HISVDCDIVR VHPDSSLAGR KGYSTVEGAL YSYLEGTRFH QTAVDMAEIY TMWPKQTEAN
EQVCLYALGE SIESVRQKCP VDDADASFPP KTVPCLCRYA MTPERVARLR MNHTTSIIVC
SSFPLPKYKI EGVQKVKCSK ALLFDHNVPS RVSPRTYRPA DEIIQTPQIP TEACQDAQFV
QSITDEAVPV PSDLEACDAT MDWPSIDIVP TRQRSDSFDS EYSSRSNIQL VTADVHAPMY
ANSLASSGGS VLSLSSEQAQ NGIMILPDSE DTDSISRVST PIAPPRRRLG RTINVTCDER
EGKILPMASD RLFTAKPYTV ALGVSTADIT AYPIQAPLGS TQPPALEQIT FGDFAEGEID
NLLTGALTFG DFEPGEVEEL TDSEWSTCSD TDEELXLDRA GGYIFSSDTG QGHLQQKSVR
QTTLPVNIVE EVHEEKCYPP KLDEIKEQLL LKRLQESAST ANRSRYQSRK VENMKATIIH
RLKEGCRLYL ASDTPRVPSY RITYPAPVYS PSISIKLNNP ETAVAVCNEF LARNYPTVAS
YQVTDEYDAY LDMVDGSESC LDRATFNPSK LRSYPKQHSY HAPTIRSAVP SPFQNTLQNV
LAAATKRNCN VTQMRELPTM DSAVFNVECF KKYACNQEYW REFASSPIRV TTENLTMYVT
KLKGPKAAAL FAKTHNLLPL QEVPMDRFTM DMKRDVKVTP GTKHTEERPK VQVIQAAEPL
ATAYLCGIHR ELVRRLNAVL LPNVHTLFDM SAEDFDAIIS THFKPGDAVL ETDIASFDKS
QDDSLALTAM MLLEDLGVDQ PILDLIEAAF GEISSCHLPT GTRFKFGAMM KSGMFLTLFV
NTLLNITIAS RVLEERLTTS ACAAFIGDDN IIHGVVSDAL MAARCATWMN MEVKIIDAVV
SEKAPYFCGG FILHDTVTGT SCRVADPLKR LFKLGKPLAA GDEQDEDRRR ALADEVTRWQ
RTGLITELEK AVYSRYEVQG ITAVITSMAT FASSKENFKK LRGPVVTLYG GPK
