ID   P19_CIRV                Reviewed;         172 AA.
AC   Q66104;
DT   15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 76.
DE   RecName: Full=RNA silencing suppressor p19;
DE   AltName: Full=19 kDa symptom severity modulator;
GN   ORFNames=ORF4;
OS   Carnation Italian ringspot virus (CIRV).
OC   Viruses; Riboviria; Orthornavirae; Kitrinoviricota; Tolucaviricetes;
OC   Tolivirales; Tombusviridae; Procedovirinae; Tombusvirus.
OX   NCBI_TaxID=39443;
OH   NCBI_TaxID=3570; Dianthus caryophyllus (Carnation) (Clove pink).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=7503699; DOI=10.1007/bf01322690;
RA   Rubino L., Burgyan J., Russo M.;
RT   "Molecular cloning and complete nucleotide sequence of carnation Italian
RT   ringspot tombusvirus genomic and defective interfering RNAs.";
RL   Arch. Virol. 140:2027-2039(1995).
RN   [2]
RP   FUNCTION, AND MUTAGENESIS OF TRP-39 AND TRP-42.
RX   PubMed=19254536; DOI=10.1016/j.bpj.2008.11.047;
RA   Xia Z., Zhu Z., Zhu J., Zhou R.;
RT   "Recognition mechanism of siRNA by viral p19 suppressor of RNA silencing: a
RT   molecular dynamics study.";
RL   Biophys. J. 96:1761-1769(2009).
RN   [3]
RP   X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS), AND FUNCTION.
RX   PubMed=14697199; DOI=10.1016/s0092-8674(03)00984-x;
RA   Vargason J.M., Szittya G., Burgyan J., Tanaka Hall T.M.;
RT   "Size selective recognition of siRNA by an RNA silencing suppressor.";
RL   Cell 115:799-811(2003).
CC   -!- FUNCTION: Acts as a suppressor of RNA-mediated gene silencing, also
CC       known as post-transcriptional gene silencing (PTGS), a mechanism of
CC       plant viral defense that limits the accumulation of viral RNAs. Binds
CC       to short interfering RNAs (siRNAs) with high affinity. Acts as a
CC       molecular caliper to specifically select siRNAs based on the length of
CC       the duplex region of the RNA. {ECO:0000269|PubMed:14697199,
CC       ECO:0000269|PubMed:19254536}.
CC   -!- SUBUNIT: Homodimer.
CC   -!- SIMILARITY: Belongs to the tombusvirus protein p19 family.
CC       {ECO:0000305}.
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DR   EMBL; X85215; CAA59481.1; -; Genomic_RNA.
DR   RefSeq; NP_612584.1; NC_003500.2.
DR   PDB; 1RPU; X-ray; 2.50 A; A/B=1-172.
DR   PDB; 6BJG; X-ray; 2.29 A; A/B=1-172.
DR   PDB; 6BJH; X-ray; 2.58 A; A/B=1-172.
DR   PDB; 6BJV; X-ray; 2.20 A; A/B=1-172.
DR   PDBsum; 1RPU; -.
DR   PDBsum; 6BJG; -.
DR   PDBsum; 6BJH; -.
DR   PDBsum; 6BJV; -.
DR   SMR; Q66104; -.
DR   GeneID; 935442; -.
DR   KEGG; vg:935442; -.
DR   EvolutionaryTrace; Q66104; -.
DR   Proteomes; UP000201384; Genome.
DR   GO; GO:0044423; C:virion component; IEA:InterPro.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.390.180; -; 1.
DR   InterPro; IPR004905; Tombusvirus_p19.
DR   InterPro; IPR036131; VP19_sf.
DR   Pfam; PF03220; Tombus_P19; 1.
DR   SUPFAM; SSF103145; SSF103145; 1.
PE   1: Evidence at protein level;
KW   3D-structure; RNA-binding; Suppressor of RNA silencing.
FT   CHAIN           1..172
FT                   /note="RNA silencing suppressor p19"
FT                   /id="PRO_0000222872"
FT   REGION          1..27
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MUTAGEN         39
FT                   /note="W->G: Complete loss of silencing suppression."
FT                   /evidence="ECO:0000269|PubMed:19254536"
FT   MUTAGEN         42
FT                   /note="W->G: Complete loss of silencing suppression."
FT                   /evidence="ECO:0000269|PubMed:19254536"
FT   STRAND          4..6
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   HELIX           7..16
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   TURN            17..19
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   STRAND          22..24
FT                   /evidence="ECO:0007829|PDB:6BJG"
FT   STRAND          29..32
FT                   /evidence="ECO:0007829|PDB:1RPU"
FT   HELIX           39..45
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   STRAND          52..55
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   STRAND          57..65
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   STRAND          68..75
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   HELIX           80..87
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   HELIX           92..99
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   TURN            100..102
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   STRAND          109..116
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   STRAND          119..126
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   HELIX           127..129
FT                   /evidence="ECO:0007829|PDB:6BJV"
FT   HELIX           130..144
FT                   /evidence="ECO:0007829|PDB:6BJV"
SQ   SEQUENCE   172 AA;  19335 MW;  EF81C6386E06C3C4 CRC64;
     MERAIQGNDT REQANGERWD GGSGGITSPF KLPDESPSWT EWRLYNDETN SNQDNPLGFK
     ESWGFGKVVF KRYLRYDRTE ASLHRVLGSW TGDSVNYAAS RFLGANQVGC TYSIRFRGVS
     VTISGGSRTL QHLCEMAIRS KQELLQLTPV EVESNVSRGC PEGIETFKKE SE