ID   E3GL_ADE06              Reviewed;         159 AA.
AC   P68979; P03251;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   02-SEP-2026, entry version 72.
DE   RecName: Full=Early E3 18.5 kDa glycoprotein;
DE   AltName: Full=E3-19K;
DE   AltName: Full=E3gp 19 kDa;
DE            Short=E19;
DE   AltName: Full=GP19K;
DE   Flags: Precursor;
OS   Human adenovirus C serotype 6 (HAdV-6) (Human adenovirus 6).
OC   Viruses; Varidnaviria; Bamfordvirae; Preplasmiviricota; Polisuviricotina;
OC   Pharingeaviricetes; Rowavirales; Adenoviridae; Mastadenovirus;
OC   Mastadenovirus hylobatidae; Mastadenovirus caesari; Human mastadenovirus C.
OX   NCBI_TaxID=10534;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Reichmann H., Schaarschmidt E., Geisler B., Hausmann J., Ortmann D.,
RA   Bauer U., Flunker G., Seidel W.;
RT   "Sequence analysis of group C human adenoviruses type 1 and 6 for five
RT   genes of region E3.";
RL   Submitted (DEC-1997) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Binds and retains class I heavy chains in the endoplasmic
CC       reticulum during the early period of virus infection, thereby impairing
CC       their transport to the cell surface. Also delays the expression of
CC       class I alleles that it cannot affect by direct retention. Binds
CC       transporters associated with antigen processing (TAP) and acts as a
CC       tapasin inhibitor, preventing class I/TAP association. 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; Single-pass
CC       type I membrane protein.
CC   -!- DEVELOPMENTAL STAGE: Expressed at early period of virus infection.
CC   -!- DOMAIN: The lumenal domain binds directly to the peptide-binding domain
CC       of class I molecules.
CC   -!- DOMAIN: The di-lysine motif confers endoplasmic reticulum localization
CC       for type I membrane proteins. {ECO:0000250}.
CC   -!- PTM: Both disulfide bonds are absolutely critical for the interaction
CC       with MHC antigens. {ECO:0000250}.
CC   -!- PTM: N-glycosylated; high-mannose. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the adenoviridae E19 family. {ECO:0000305}.
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DR   EMBL; Y16037; CAA75990.1; -; Genomic_DNA.
DR   PDB; 4E5X; X-ray; 1.95 A; G/H=18-117.
DR   SMR; P68979; -.
DR   EvolutionaryTrace; P68979; -.
DR   GO; GO:0044167; C:host cell endoplasmic reticulum membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0005537; F:D-mannose binding; IEA:UniProtKB-KW.
DR   GO; GO:0046776; P:symbiont-mediated suppression of host antigen processing and presentation of peptide antigen via MHC class I; IEA:UniProtKB-KW.
DR   FunFam; 2.60.40.3530:FF:000002; Early E3 18.5 kDa glycoprotein; 1.
DR   Gene3D; 2.60.40.3530; -; 1.
DR   InterPro; IPR006965; Adenovirus_Gp19K.
DR   InterPro; IPR038710; Adenovirus_Gp19K_sf.
DR   Pfam; PF04881; Adeno_GP19K; 1.
DR   PDBsum; 4E5X; -.
PE   1: Evidence at protein level;
KW   3D-structure; Disulfide bond; Early protein; Glycoprotein;
KW   Host endoplasmic reticulum; Host membrane; Host-virus interaction;
KW   Inhibition of host adaptive immune response by virus;
KW   Inhibition of host tapasin by virus; Lectin; Mannose-binding; Membrane;
KW   Signal; Transmembrane; Transmembrane helix; Viral immunoevasion.
FT   SIGNAL          1..17
FT                   /evidence="ECO:0000250"
FT   CHAIN           18..159
FT                   /note="Early E3 18.5 kDa glycoprotein"
FT                   /id="PRO_0000036485"
FT   TOPO_DOM        18..123
FT                   /note="Lumenal"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        124..144
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        145..159
FT                   /note="Cytoplasmic"
FT                   /evidence="ECO:0000255"
FT   MOTIF           156..159
FT                   /note="Di-lysine motif"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        29
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        78
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   DISULFID        28..45
FT                   /evidence="ECO:0000250"
FT   DISULFID        39..100
FT                   /evidence="ECO:0000250"
FT   HELIX           23..26
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   STRAND          27..35
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   STRAND          38..46
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   STRAND          48..56
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   STRAND          59..69
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   STRAND          76..83
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   STRAND          86..93
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   HELIX           96..103
FT                   /evidence="ECO:0007829|PDB:4E5X"
FT   HELIX           105..109
FT                   /evidence="ECO:0007829|PDB:4E5X"
SQ   SEQUENCE   159 AA;  18438 MW;  ED2519547E18AEB0 CRC64;
     MRYMILGLLA LAAVCSAAKK VEFKEPACNV TFKSEANECT TLIKCTTEHE KLIIRHKDKI
     GKYAVYAIWQ PGDTNDYNVT VFQGENRKTF MYKFPFYEMC DITMYMSKQY KLWPPQKCLE
     NTGTFCSTAL LITALALVCT LLYLKYKSRR SFIDEKKMP
//