AP3A_BCHK3
ID AP3A_BCHK3 Reviewed; 274 AA.
AC Q3LZX0;
DT 12-JUN-2007, integrated into UniProtKB/Swiss-Prot.
DT 25-OCT-2005, sequence version 1.
DT 23-FEB-2022, entry version 75.
DE RecName: Full=Protein 3;
DE AltName: Full=Accessory protein 3;
GN ORFNames=3;
OS Bat coronavirus HKU3 (BtCoV) (SARS-like coronavirus HKU3).
OC Viruses; Riboviria; Orthornavirae; Pisuviricota; Pisoniviricetes;
OC Nidovirales; Cornidovirineae; Coronaviridae; Orthocoronavirinae;
OC Betacoronavirus; Sarbecovirus.
OX NCBI_TaxID=442736;
OH NCBI_TaxID=89399; Rhinolophus sinicus (Chinese rufous horseshoe bat).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RC STRAIN=Isolate HKU3-1;
RX PubMed=16169905; DOI=10.1073/pnas.0506735102;
RA Lau S.K.P., Woo P.C.Y., Li K.S.M., Huang Y., Tsoi H.-W., Wong B.H.L.,
RA Wong S.S.Y., Leung S.-Y., Chan K.-H., Yuen K.-Y.;
RT "Severe acute respiratory syndrome coronavirus-like virus in Chinese
RT horseshoe bats.";
RL Proc. Natl. Acad. Sci. U.S.A. 102:14040-14045(2005).
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. Down-regulates 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 (By similarity). {ECO:0000250}.
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 (By similarity). {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Virion {ECO:0000250}. Host Golgi apparatus
CC membrane {ECO:0000250}; Multi-pass membrane protein {ECO:0000250}. Host
CC cell membrane {ECO:0000250}; Multi-pass membrane protein {ECO:0000250}.
CC Secreted {ECO:0000250}. Host cytoplasm {ECO:0000250}. Note=The cell
CC surface expressed protein can undergo endocytosis. The protein is
CC secreted in association with membranous structures (By similarity).
CC {ECO:0000250}.
CC -!- DOMAIN: The second or the third transmembrane region are responsible
CC for Golgi localization. {ECO:0000250}.
CC -!- PTM: Exists in both O-glycosylated and non-glycosylated forms. The
CC glycosylated form is associated with the virion (By similarity).
CC {ECO:0000250}.
CC -!- MISCELLANEOUS: Bat coronavirus HKU3 is highly similar to SARS-CoV
CC (SARS-like).
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DR EMBL; DQ022305; AAY88867.1; -; Genomic_RNA.
DR SMR; Q3LZX0; -.
DR Proteomes; UP000007450; 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:0044385; C:integral to membrane of host cell; IEA:UniProtKB-KW.
DR GO; GO:0005216; F:ion channel activity; IEA:UniProtKB-KW.
DR GO; GO:0039707; P:pore formation by virus in membrane of host cell; IEA:UniProtKB-KW.
DR GO; GO:0051259; P:protein complex oligomerization; IEA:UniProtKB-KW.
DR CDD; cd21648; SARS-CoV-like_ORF3a; 1.
DR InterPro; IPR024407; Protein_3a_bCoV.
DR Pfam; PF11289; bCoV_viroporin; 1.
DR PROSITE; PS51967; COV_VIROPORIN_3A_CD; 1.
DR PROSITE; PS51966; COV_VIROPORIN_3A_TM; 1.
PE 3: Inferred from homology;
KW Apoptosis; Glycoprotein; Host cell membrane; Host cytoplasm;
KW Host Golgi apparatus; Host membrane; Ion channel; Ion transport; Membrane;
KW Secreted; Transmembrane; Transmembrane helix; Transport; Viral ion channel;
KW Virion.
FT CHAIN 1..274
FT /note="Protein 3"
FT /id="PRO_0000291328"
FT TOPO_DOM 1..34
FT /note="Extracellular"
FT /evidence="ECO:0000250"
FT TRANSMEM 35..55
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 56..78
FT /note="Cytoplasmic"
FT /evidence="ECO:0000255"
FT TRANSMEM 79..99
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 100..104
FT /note="Extracellular"
FT /evidence="ECO:0000255"
FT TRANSMEM 105..125
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 126..274
FT /note="Cytoplasmic"
FT /evidence="ECO:0000250"
FT DOMAIN 33..141
FT /note="CoV 3a-like viroporin TM"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01311"
FT DOMAIN 145..237
FT /note="CoV 3a-like viroporin CD"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01312"
FT SITE 133
FT /note="Involved in polymerization"
FT /evidence="ECO:0000250"
FT CARBOHYD 27
FT /note="O-linked (GalNAc...) serine; by host"
FT /evidence="ECO:0000255"
FT CARBOHYD 28
FT /note="O-linked (GalNAc...) threonine; by host"
FT /evidence="ECO:0000250"
FT CARBOHYD 32
FT /note="O-linked (GalNAc...) threonine; by host"
FT /evidence="ECO:0000250"
FT CARBOHYD 34
FT /note="O-linked (GalNAc...) threonine; by host"
FT /evidence="ECO:0000255"
SQ SEQUENCE 274 AA; 30984 MW; D5D4AB36E610187C CRC64;
MDLFMSIFTL GAITRNPAKI ENASPASTVH ATATIPLQAT FPFGWLIVGV ALLAVFQSAS
KVIALHRRWQ LALYKGVQLV CNMLLLFVTI YSHLLLLAAC MEAQFLYIYA LIYILQIVSF
CRFIMRCWLC WKCRSKNPLL YDANYFVCWH TNNYDYCIPY NSVTDTVVIT SGDGTNQPKL
KEDYQIGGYS EDWHSGVKDY VVIYGYFTEV YYQLESTQLS TDTGAENATF FIYSKLVKDV
DHVQIHTIDG SSGVVNPAMD PIYDEPTTTT SVPL
