ID   US06_HCMVT              Reviewed;         183 AA.
AC   P60528;
DT   01-MAR-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2004, sequence version 1.
DT   23-FEB-2022, entry version 59.
DE   RecName: Full=Unique short US6 glycoprotein;
DE   AltName: Full=HXLF6;
DE   AltName: Full=gpUS6;
DE   Flags: Precursor;
GN   Name=US6;
OS   Human cytomegalovirus (strain Towne) (HHV-5) (Human herpesvirus 5).
OC   Viruses; Duplodnaviria; Heunggongvirae; Peploviricota; Herviviricetes;
OC   Herpesvirales; Herpesviridae; Betaherpesvirinae; Cytomegalovirus.
OX   NCBI_TaxID=10363;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=12535225; DOI=10.1034/j.1399-3089.2003.01116.x;
RA   Crew M.D., Phanavanh B.;
RT   "Exploiting virus stealth technology for xenotransplantation: reduced human
RT   T cell responses to porcine cells expressing herpes simplex virus ICP47.";
RL   Xenotransplantation 10:50-59(2003).
CC   -!- FUNCTION: Inhibits peptide loading of MHC class I molecules by
CC       transporters associated with antigen processing (TAP). Does not prevent
CC       peptide binding to TAP, but binds to the lumenal side of the TAP
CC       complex and inhibits peptide translocation by specifically blocking
CC       ATP-binding to TAP1, but not TAP2. Also prevents the conformational
CC       rearrangement of TAP induced by peptide binding. In consequence,
CC       infected cells are masked for immune recognition by cytotoxic T-
CC       lymphocytes (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Host endoplasmic reticulum membrane
CC       {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}.
CC   -!- DEVELOPMENTAL STAGE: Expressed at early period of virus infection.
CC   -!- DOMAIN: The ER-lumenal domain is responsible for TAP inhibition. It is
CC       sufficient to inhibit ATP binding to TAP (By similarity).
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the cytomegalovirus US6 family. {ECO:0000305}.
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DR   EMBL; AY072775; AAL67143.1; -; Genomic_DNA.
DR   GO; GO:0044167; C:host cell endoplasmic reticulum membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0039588; P:suppression by virus of host antigen processing and presentation; IEA:UniProtKB-KW.
DR   InterPro; IPR035129; US6.
DR   Pfam; PF17616; US6; 1.
PE   2: Evidence at transcript level;
KW   Disulfide bond; Early protein; Glycoprotein; Host endoplasmic reticulum;
KW   Host membrane; Host-virus interaction; Immunoglobulin domain;
KW   Inhibition of host adaptive immune response by virus;
KW   Inhibition of host TAP by virus; Membrane; Signal; Transmembrane;
KW   Transmembrane helix; Viral immunoevasion.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000255"
FT   CHAIN           20..183
FT                   /note="Unique short US6 glycoprotein"
FT                   /id="PRO_0000037439"
FT   TOPO_DOM        20..144
FT                   /note="Lumenal"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        145..165
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        166..183
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          30..131
FT                   /note="Ig-like H-type"
FT   CARBOHYD        52
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   DISULFID        39..127
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   183 AA;  20639 MW;  C3722E9F011C0023 CRC64;
     MDLLIRLGFL LMCALPTPGE RSSRDPKTLL SLSPRQQACV PRTKSHRPVC YNDTGDCTDA
     DDSWKQLGED FAHQCLQAAK KRPKTHKSRP NDRNLEGRLT CQRVRRLLPC DLDIHPSHRL
     LTLMNNCVCD GAVWNAFRLI ERHGFFAVTL YLCCGITLLV VILALLCSIT YESTGRGIRR
     CGS