HBSAG_HBVGB
ID HBSAG_HBVGB Reviewed; 389 AA.
AC P87745;
DT 26-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-1997, sequence version 1.
DT 03-AUG-2022, entry version 75.
DE RecName: Full=Large envelope protein {ECO:0000255|HAMAP-Rule:MF_04075};
DE AltName: Full=L glycoprotein {ECO:0000255|HAMAP-Rule:MF_04075};
DE AltName: Full=L-HBsAg {ECO:0000255|HAMAP-Rule:MF_04075};
DE Short=LHB {ECO:0000255|HAMAP-Rule:MF_04075};
DE AltName: Full=Large S protein {ECO:0000255|HAMAP-Rule:MF_04075};
DE AltName: Full=Large surface protein {ECO:0000255|HAMAP-Rule:MF_04075};
DE AltName: Full=Major surface antigen {ECO:0000255|HAMAP-Rule:MF_04075};
GN Name=S {ECO:0000255|HAMAP-Rule:MF_04075};
OS Gibbon hepatitis B virus subtype ayw3q (isolate Hope) (HBVgbn).
OC Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC Blubervirales; Hepadnaviridae; Orthohepadnavirus.
OX NCBI_TaxID=489544;
OH NCBI_TaxID=9577; Hylobatidae (gibbons).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=8615024; DOI=10.1006/viro.1996.0181;
RA Norder H., Ebert J.W., Fields H.A., Mushahwar I.K., Magnius L.O.;
RT "Complete sequencing of a gibbon hepatitis B virus genome reveals a unique
RT genotype distantly related to the chimpanzee hepatitis B virus.";
RL Virology 218:214-223(1996).
RN [2]
RP REVIEW.
RX PubMed=8957666; DOI=10.1159/000150471;
RA Bruss V., Gerhardt E., Vieluf K., Wunderlich G.;
RT "Functions of the large hepatitis B virus surface protein in viral particle
RT morphogenesis.";
RL Intervirology 39:23-31(1996).
RN [3]
RP REVIEW.
RX PubMed=9498079; DOI=10.1007/978-1-4615-5383-0_20;
RA Block T.M., Lu X., Mehta A., Park J., Blumberg B.S., Dwek R.;
RT "Role of glycan processing in hepatitis B virus envelope protein
RT trafficking.";
RL Adv. Exp. Med. Biol. 435:207-216(1998).
RN [4]
RP REVIEW.
RX PubMed=15567498; DOI=10.1016/j.virusres.2004.08.016;
RA Bruss V.;
RT "Envelopment of the hepatitis B virus nucleocapsid.";
RL Virus Res. 106:199-209(2004).
RN [5]
RP REVIEW.
RX PubMed=16863502; DOI=10.1111/j.1349-7006.2006.00235.x;
RA Wang H.C., Huang W., Lai M.D., Su I.J.;
RT "Hepatitis B virus pre-S mutants, endoplasmic reticulum stress and
RT hepatocarcinogenesis.";
RL Cancer Sci. 97:683-688(2006).
CC -!- FUNCTION: The large envelope protein exists in two topological
CC conformations, one which is termed 'external' or Le-HBsAg and the other
CC 'internal' or Li-HBsAg. In its external conformation the protein
CC attaches the virus to cell receptors and thereby initiating infection.
CC This interaction determines the species specificity and liver tropism.
CC This attachment induces virion internalization predominantly through
CC caveolin-mediated endocytosis. The large envelope protein also assures
CC fusion between virion membrane and endosomal membrane. In its internal
CC conformation the protein plays a role in virion morphogenesis and
CC mediates the contact with the nucleocapsid like a matrix protein.
CC {ECO:0000255|HAMAP-Rule:MF_04075}.
CC -!- FUNCTION: The middle envelope protein plays an important role in the
CC budding of the virion. It is involved in the induction of budding in a
CC nucleocapsid independent way. In this process the majority of envelope
CC proteins bud to form subviral lipoprotein particles of 22 nm of
CC diameter that do not contain a nucleocapsid. {ECO:0000255|HAMAP-
CC Rule:MF_04075}.
CC -!- SUBUNIT: [Isoform L]: In its internal form (Li-HBsAg), interacts with
CC the capsid protein and with the isoform S. Interacts with host
CC chaperone CANX. {ECO:0000250|UniProtKB:P03141}.
CC -!- SUBUNIT: [Isoform M]: Associates with host chaperone CANX through its
CC pre-S2 N glycan; this association may be essential for isoform M proper
CC secretion. {ECO:0000250|UniProtKB:P03141}.
CC -!- SUBUNIT: [Isoform S]: Interacts with isoform L. Interacts with the
CC antigens of satellite virus HDV (HDVAgs); this interaction is required
CC for encapsidation of HDV genomic RNA. {ECO:0000250|UniProtKB:P03141}.
CC -!- SUBCELLULAR LOCATION: Virion membrane {ECO:0000255|HAMAP-
CC Rule:MF_04075}.
CC -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing, Alternative initiation; Named isoforms=3;
CC Name=L; Synonyms=Large envelope protein, LHB, L-HBsAg;
CC IsoId=P87745-1; Sequence=Displayed;
CC Name=M; Synonyms=Middle envelope protein, MHB, M-HBsAg;
CC IsoId=P87745-2; Sequence=VSP_031465;
CC Name=S; Synonyms=Small envelope protein, SHB, S-HBsAg;
CC IsoId=P87745-3; Sequence=VSP_031464;
CC -!- DOMAIN: The large envelope protein is synthesized with the pre-S region
CC at the cytosolic side of the endoplasmic reticulum and, hence will be
CC within the virion after budding. Therefore the pre-S region is not N-
CC glycosylated. Later a post-translational translocation of N-terminal
CC pre-S and TM1 domains occur in about 50% of proteins at the virion
CC surface. These molecules change their topology by an unknown mechanism,
CC resulting in exposure of pre-S region at virion surface. For isoform M
CC in contrast, the pre-S2 region is translocated cotranslationally to the
CC endoplasmic reticulum lumen and is N-glycosylated. {ECO:0000255|HAMAP-
CC Rule:MF_04075}.
CC -!- PTM: Isoform M is N-terminally acetylated by host at a ratio of 90%,
CC and N-glycosylated by host at the pre-S2 region.
CC {ECO:0000250|UniProtKB:P03138, ECO:0000255|HAMAP-Rule:MF_04075}.
CC -!- PTM: Myristoylated. {ECO:0000255|HAMAP-Rule:MF_04075}.
CC -!- SIMILARITY: Belongs to the orthohepadnavirus major surface antigen
CC family. {ECO:0000255|HAMAP-Rule:MF_04075}.
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DR EMBL; U46935; AAB41952.1; -; Genomic_DNA.
DR PIR; S67506; S67506.
DR SMR; P87745; -.
DR Proteomes; UP000007408; Genome.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-UniRule.
DR GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0075513; P:caveolin-mediated endocytosis of virus by host cell; IEA:UniProtKB-KW.
DR GO; GO:0039654; P:fusion of virus membrane with host endosome membrane; IEA:UniProtKB-KW.
DR GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-UniRule.
DR HAMAP; MF_04075; HBV_HBSAG; 1.
DR InterPro; IPR000349; HBV_HBSAG.
DR Pfam; PF00695; vMSA; 1.
PE 3: Inferred from homology;
KW Acetylation; Alternative initiation; Alternative splicing;
KW Caveolin-mediated endocytosis of virus by host;
KW Fusion of virus membrane with host endosomal membrane;
KW Fusion of virus membrane with host membrane; Glycoprotein;
KW Host-virus interaction; Lipoprotein; Membrane; Myristate; Transmembrane;
KW Transmembrane helix; Viral attachment to host cell;
KW Viral penetration into host cytoplasm; Virion; Virus endocytosis by host;
KW Virus entry into host cell.
FT INIT_MET 1
FT /note="Removed; by host"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT CHAIN 2..389
FT /note="Large envelope protein"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT /id="PRO_0000319291"
FT TOPO_DOM 2..242
FT /note="Intravirion; in internal conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 2..170
FT /note="Virion surface; in external conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 171..191
FT /note="Helical; Name=TM1; Note=In external conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 192..242
FT /note="Intravirion; in external conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 243..263
FT /note="Helical; Name=TM2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 264..337
FT /note="Virion surface"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 338..358
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 359..364
FT /note="Intravirion"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 365..387
FT /note="Helical; Name=TM3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 388..389
FT /note="Virion surface"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT REGION 2..163
FT /note="Pre-S"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT REGION 2..108
FT /note="Pre-S1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT REGION 79..99
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 109..163
FT /note="Pre-S2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT COMPBIAS 82..97
FT /note="Polar residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT LIPID 2
FT /note="N-myristoyl glycine; by host"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT CARBOHYD 309
FT /note="N-linked (GlcNAc...) asparagine; by host"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT VAR_SEQ 1..163
FT /note="Missing (in isoform S)"
FT /evidence="ECO:0000305"
FT /id="VSP_031464"
FT VAR_SEQ 1..108
FT /note="Missing (in isoform M)"
FT /evidence="ECO:0000305"
FT /id="VSP_031465"
FT MOD_RES P87745-2:1
FT /note="N-acetylmethionine"
FT /evidence="ECO:0000250|UniProtKB:P03138"
SQ SEQUENCE 389 AA; 42719 MW; 4AF6252245BE7162 CRC64;
MGQNLSVSNP LGFFPEHQLD PLFKANSNNP DWDFNPNKDN WPEATKVGVG AFGPGFTPPH
GGLLGWSSQA QGAITTLPAL PPPAATNRQS GRQPTPISPP LRDTHPQAMK WNSTVFHQTL
QDPRVRGLYF PVGGSSSGTV NPVPTTASHI SSIFSRTGDP APNMENITSG FLGPLLVLQA
GFFLLTKILT IPQSLDSWWT SLNFLGGAPV CPGQNSQSPT SNHSPTSCPP ICPGYRWMCL
RRFIIFLFIL LLCLIFLLVL LDYQGMLPVC PLLPGSSTTS TGPCRTCTIT AQGTSLYPSC
CCTKPSDGNC TCIPIPSSWA FAKFLWEWAS VRFSWLSLLA PFVQWFAGLS PTAWLLVIWM
IWYWGPNLYN ILNPFIPLLP IFFCLWVYI
