SIGM3_REOVD
ID SIGM3_REOVD Reviewed; 365 AA.
AC P03527; A4ZY29; Q99AV2;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 22-JUL-2008, sequence version 2.
DT 23-FEB-2022, entry version 103.
DE RecName: Full=Outer capsid protein sigma-3;
DE Short=Sigma3;
GN Name=S4;
OS Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3).
OC Viruses; Riboviria; Orthornavirae; Duplornaviricota; Resentoviricetes;
OC Reovirales; Reoviridae; Spinareovirinae; Orthoreovirus.
OX NCBI_TaxID=10886;
OH NCBI_TaxID=40674; Mammalia.
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX PubMed=6492267; DOI=10.1128/jvi.52.3.984-987.1984;
RA Giantini M., Seliger L.S., Furuichi Y., Shatkin A.J.;
RT "Reovirus type 3 genome segment S4: nucleotide sequence of the gene
RT encoding a major virion surface protein.";
RL J. Virol. 52:984-987(1984).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RC STRAIN=Isolate D-EA1, and Isolate D-EA3;
RX PubMed=11238846; DOI=10.1128/jvi.75.7.3197-3206.2001;
RA Ebert D.H., Wetzel J.D., Brumbaugh D.E., Chance S.R., Stobie L.E.,
RA Baer G.S., Dermody T.S.;
RT "Adaptation of reovirus to growth in the presence of protease inhibitor E64
RT segregates with a mutation in the carboxy terminus of viral outer-capsid
RT protein sigma3.";
RL J. Virol. 75:3197-3206(2001).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RC STRAIN=Infectious clone;
RX PubMed=18005692; DOI=10.1016/j.chom.2007.03.003;
RA Kobayashi T., Antar A.A., Boehme K.W., Danthi P., Eby E.A., Guglielmi K.M.,
RA Holm G.H., Johnson E.M., Maginnis M.S., Naik S., Skelton W.B., Wetzel J.D.,
RA Wilson G.J., Chappell J.D., Dermody T.S.;
RT "A plasmid-based reverse genetics system for animal double-stranded RNA
RT viruses.";
RL Cell Host Microbe 1:147-157(2007).
RN [4]
RP FUNCTION.
RX PubMed=9268168; DOI=10.1006/viro.1997.8664;
RA Yue Z., Shatkin A.J.;
RT "Double-stranded RNA-dependent protein kinase (PKR) is regulated by
RT reovirus structural proteins.";
RL Virology 234:364-371(1997).
RN [5]
RP X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS), AND ZINC-FINGER.
RX PubMed=11230122; DOI=10.1093/emboj/20.5.979;
RA Olland A.M., Jane-Valbuena J., Schiff L.A., Nibert M.L., Harrison S.C.;
RT "Structure of the reovirus outer capsid and dsRNA-binding protein sigma3 at
RT 1.8 A resolution.";
RL EMBO J. 20:979-989(2001).
CC -!- FUNCTION: Stimulates translation by blocking the activation of the
CC dsRNA-dependent protein kinase EIF2AK2/PKR, thereby inhibiting the host
CC interferon response. Sigma3 prevents the activation of EIF2AK2 by
CC competing with the kinase for dsRNA-binding.
CC {ECO:0000269|PubMed:9268168}.
CC -!- FUNCTION: The viral outer shell polypeptides, of which sigma-3 is one,
CC impose structural constraints that prevent elongation of nascent
CC transcripts by the RNA-dependent RNA polymerase lambda-3.
CC {ECO:0000250}.
CC -!- SUBUNIT: Heterohexamer of three sigma-3 and three Mu-1 proteins (By
CC similarity). The RNA-binding form is probably a homodimer.
CC {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Virion. Note=Found in the outer capsid. Each
CC subunit is positioned with the small lobe anchoring it to the protein
CC mu1 on the surface of the virion, and the large lobe, the site of
CC initial cleavages during entry-related proteolytic disassembly,
CC protruding outwards.
CC -!- PTM: Cleaved during virus the endosomal proteolytic disassembly of the
CC outer capsid.
CC -!- SIMILARITY: Belongs to the orthoreovirus sigma-3 protein family.
CC {ECO:0000305}.
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DR EMBL; K02739; AAA47283.1; -; Genomic_RNA.
DR EMBL; AF332137; AAK07648.1; -; Genomic_RNA.
DR EMBL; EF494444; ABP48922.1; -; Genomic_RNA.
DR PIR; A04127; MNXRS3.
DR PDB; 1FN9; X-ray; 1.80 A; A/B=1-365.
DR PDB; 7LUP; EM; 6.20 A; Q=1-365.
DR PDBsum; 1FN9; -.
DR PDBsum; 7LUP; -.
DR SMR; P03527; -.
DR PRIDE; P03527; -.
DR EvolutionaryTrace; P03527; -.
DR Proteomes; UP000006373; Genome.
DR GO; GO:0039624; C:viral outer capsid; IEA:UniProtKB-KW.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0030291; F:protein serine/threonine kinase inhibitor activity; IEA:UniProtKB-KW.
DR GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
DR GO; GO:0039580; P:suppression by virus of host PKR signaling; IEA:UniProtKB-KW.
DR GO; GO:0039502; P:suppression by virus of host type I interferon-mediated signaling pathway; IEA:UniProtKB-KW.
DR GO; GO:0019058; P:viral life cycle; IEA:InterPro.
DR InterPro; IPR000153; Reo_capsid_sigma3.
DR InterPro; IPR023634; Reovirus_capsid_sigma-3_dom_sf.
DR Pfam; PF00979; Reovirus_cap; 1.
DR SUPFAM; SSF64465; SSF64465; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Capsid protein; Host-virus interaction;
KW Inhibition of host innate immune response by virus;
KW Inhibition of host interferon signaling pathway by virus;
KW Inhibition of host PKR by virus; Interferon antiviral system evasion;
KW Metal-binding; Outer capsid protein; Reference proteome; RNA-binding;
KW Transcription; Transcription regulation; Translation regulation;
KW Viral immunoevasion; Virion; Zinc; Zinc-finger.
FT CHAIN 1..365
FT /note="Outer capsid protein sigma-3"
FT /id="PRO_0000222752"
FT ZN_FING 51..73
FT /note="CCHC-type"
FT VARIANT 354
FT /note="Y -> H (in strain: Isolate D-EA1 and Isolate D-EA3;
FT altered susceptibility to proteolysis during virus
FT disassembly)"
FT CONFLICT 133
FT /note="W -> R (in Ref. 1; AAA47283)"
FT /evidence="ECO:0000305"
FT CONFLICT 198
FT /note="G -> E (in Ref. 1; AAA47283)"
FT /evidence="ECO:0000305"
FT HELIX 8..18
FT /evidence="ECO:0007829|PDB:1FN9"
FT TURN 19..21
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 25..27
FT /evidence="ECO:0007829|PDB:1FN9"
FT TURN 28..30
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 41..45
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 48..51
FT /evidence="ECO:0007829|PDB:1FN9"
FT TURN 52..54
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 57..60
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 61..63
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 79..111
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 115..124
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 126..130
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 133..135
FT /evidence="ECO:0007829|PDB:1FN9"
FT TURN 141..143
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 159..176
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 180..186
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 189..192
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 199..203
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 221..223
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 226..230
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 232..234
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 236..242
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 246..249
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 252..254
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 259..261
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 270..272
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 275..277
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 282..284
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 288..292
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 293..295
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 296..305
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 308..315
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 319..334
FT /evidence="ECO:0007829|PDB:1FN9"
FT HELIX 338..341
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 351..354
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 356..358
FT /evidence="ECO:0007829|PDB:1FN9"
FT STRAND 362..365
FT /evidence="ECO:0007829|PDB:1FN9"
SQ SEQUENCE 365 AA; 41118 MW; CF50174AA43244EB CRC64;
MEVCLPNGHQ VVDLINNAFE GRVSIYSAQE GWDKTISAQP DMMVCGGAVV CMHCLGVVGS
LQRKLKHLPH HRCNQQIRHQ DYVDVQFADR VTAHWKRGML SFVAQMHEMM NDVSPDDLDR
VRTEGGSLVE LNWLQVDPNS MFRSIHSSWT DPLQVVDDLD TKLDQYWTAL NLMIDSSDLI
PNFMMRDPSH AFNGVKLGGD ARQTQFSRTF DSRSSLEWGV MVYDYSELEH DPSKGRAYRK
ELVTPARDFG HFGLSHYSRA TTPILGKMPA VFSGMLTGNC KMYPFIKGTA KLKTVRKLVE
AVNHAWGVEK IRYALGPGGM TGWYNRTMQQ APIVLTPAAL TMFPDTIKFG DLNYPVMIGD
PMILG
