ID   AP3A_SARS2              Reviewed;         275 AA.
AC   P0DTC3;
DT   22-APR-2020, integrated into UniProtKB/Swiss-Prot.
DT   22-APR-2020, sequence version 1.
DT   12-AUG-2020, entry version 3.
DE   RecName: Full=ORF3a protein;
DE   AltName: Full=Accessory protein 3a;
DE   AltName: Full=Protein 3a;
DE   AltName: Full=Protein U274;
DE   AltName: Full=Protein X1;
GN   ORFNames=3a;
OS   Severe acute respiratory syndrome coronavirus 2 (2019-nCoV) (SARS-CoV-2).
OC   Viruses; Riboviria; Nidovirales; Cornidovirineae; Coronaviridae;
OC   Orthocoronavirinae; Betacoronavirus; Sarbecovirus.
OX   NCBI_TaxID=2697049;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=32015508; DOI=10.1038/s41586-020-2008-3;
RA   Wu F., Zhao S., Yu B., Chen Y.-M., Wang W., Song Z.-G., Hu Y., Tao Z.-W.,
RA   Tian J.-H., Pei Y.-Y., Yuan M.-L., Zhang Y.-L., Dai F.-H., Liu Y.,
RA   Wang Q.-M., Zheng J.-J., Xu L., Holmes E.C., Zhang Y.-Z.;
RT   "A new coronavirus associated with human respiratory disease in China.";
RL   Nature 579:265-269(2020).
CC   -!- FUNCTION: Forms homotetrameric potassium sensitive ion channels
CC       (viroporin) and may modulate virus release. Up-regulates expression of
CC       fibrinogen subunits FGA, FGB and FGG in host lung epithelial cells.
CC       Induces apoptosis in cell culture. Downregulates the type 1 interferon
CC       receptor by inducing serine phosphorylation within the IFN alpha-
CC       receptor subunit 1 (IFNAR1) degradation motif and increasing IFNAR1
CC       ubiquitination. {ECO:0000250|UniProtKB:P59632}.
CC   -!- SUBUNIT: Homotetramer composed of two homodimers linked non covalently.
CC       Interacts with M, S and E proteins. Also interacts with the accessory
CC       protein 7a. {ECO:0000250|UniProtKB:P59632}.
CC   -!- SUBCELLULAR LOCATION: Virion {ECO:0000250|UniProtKB:P59632}. Host Golgi
CC       apparatus membrane {ECO:0000250|UniProtKB:P59632}; Multi-pass membrane
CC       protein {ECO:0000250|UniProtKB:P59632}. Host cell membrane
CC       {ECO:0000250|UniProtKB:P59632}; Multi-pass membrane protein
CC       {ECO:0000250|UniProtKB:P59632}. Secreted
CC       {ECO:0000250|UniProtKB:P59632}. Host cytoplasm
CC       {ECO:0000250|UniProtKB:P59632}. Note=The cell surface expressed protein
CC       can undergo endocytosis. The protein is secreted in association with
CC       membranous structures. {ECO:0000250|UniProtKB:P59632}.
CC   -!- DOMAIN: The second or the third transmembrane region are responsible
CC       for Golgi localization. {ECO:0000250|UniProtKB:P59632}.
CC   -!- PTM: Exists in both O-glycosylated and non-glycosylated forms. The
CC       glycosylated form is associated with the virion.
CC       {ECO:0000250|UniProtKB:P59632}.
DR   EMBL; MN908947; QHD43417.1; -; Genomic_RNA.
DR   RefSeq; YP_009724391.1; NC_045512.2.
DR   SMR; P0DTC3; -.
DR   BioGRID; 4383868; 8.
DR   IntAct; P0DTC3; 38.
DR   GlyGen; P0DTC3; 2 sites.
DR   GeneID; 43740569; -.
DR   Proteomes; UP000464024; Genome.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0044178; C:host cell Golgi membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0019012; C:virion; IEA:UniProtKB-SubCell.
DR   InterPro; IPR024407; Protein_3a_bCoV.
DR   Pfam; PF11289; APA3_viroporin; 1.
PE   3: Inferred from homology;
KW   Glycoprotein; Host cell membrane; Host cytoplasm; Host Golgi apparatus;
KW   Host membrane; Membrane; Reference proteome; Secreted; Transmembrane;
KW   Transmembrane helix; Virion.
FT   CHAIN           1..275
FT                   /note="ORF3a protein"
FT                   /id="PRO_0000449650"
FT   TRANSMEM        35..55
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        71..91
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        94..114
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   SITE            133
FT                   /note="Involved in polymerization"
FT                   /evidence="ECO:0000250|UniProtKB:P59632"
FT   CARBOHYD        32
FT                   /note="O-linked (GalNAc...) threonine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P59632"
FT   CARBOHYD        34
FT                   /note="O-linked (GalNAc...) threonine; by host"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   275 AA;  31123 MW;  4688E6D477E031C4 CRC64;
     MDLFMRIFTI GTVTLKQGEI KDATPSDFVR ATATIPIQAS LPFGWLIVGV ALLAVFQSAS
     KIITLKKRWQ LALSKGVHFV CNLLLLFVTV YSHLLLVAAG LEAPFLYLYA LVYFLQSINF
     VRIIMRLWLC WKCRSKNPLL YDANYFLCWH TNCYDYCIPY NSVTSSIVIT SGDGTTSPIS
     EHDYQIGGYT EKWESGVKDC VVLHSYFTSD YYQLYSTQLS TDTGVEHVTF FIYNKIVDEP
     EEHVQIHTID GSSGVVNPVM EPIYDEPTTT TSVPL
//