HBSAG_GSHV
ID HBSAG_GSHV Reviewed; 428 AA.
AC P03144;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 1.
DT 02-JUN-2021, entry version 87.
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 Ground squirrel hepatitis virus (strain 27) (GSHV).
OC Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC Blubervirales; Hepadnaviridae; Orthohepadnavirus.
OX NCBI_TaxID=10406;
OH NCBI_TaxID=34862; Otospermophilus beecheyi (California ground squirrel) (Spermophilus beecheyi).
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=6086950; DOI=10.1128/jvi.51.2.367-375.1984;
RA Seeger C., Ganem D., Varmus H.E.;
RT "Nucleotide sequence of an infectious molecularly cloned genome of ground
RT squirrel hepatitis virus.";
RL J. Virol. 51:367-375(1984).
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=P03144-1; Sequence=Displayed;
CC Name=M; Synonyms=Middle envelope protein, MHB, M-HBsAg;
CC IsoId=P03144-2; Sequence=VSP_031449;
CC Name=S; Synonyms=Small envelope protein, SHB, S-HBsAg;
CC IsoId=P03144-3; Sequence=VSP_031448;
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. {ECO:0000255|HAMAP-
CC 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}.
CC -!- SEQUENCE CAUTION:
CC Sequence=AAA46757.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR EMBL; K02715; AAA46757.1; ALT_INIT; Genomic_DNA.
DR PIR; A03709; SAVLS.
DR RefSeq; NP_040995.1; NC_001484.1. [P03144-2]
DR GeneID; 1488458; -.
DR KEGG; vg:1488458; -.
DR Proteomes; UP000009156; 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;
KW Reference proteome; Transmembrane; Transmembrane helix;
KW Viral attachment to host cell; Viral penetration into host cytoplasm;
KW Virion; Virus endocytosis by host; 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..428
FT /note="Large envelope protein"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT /id="PRO_0000038083"
FT TOPO_DOM 2..283
FT /note="Intravirion; in internal conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 2..211
FT /note="Virion surface; in external conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 212..232
FT /note="Helical; Name=TM1; Note=In external conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 233..283
FT /note="Intravirion; in external conformation"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 284..304
FT /note="Helical; Name=TM2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 305..376
FT /note="Virion surface"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 377..397
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 398..403
FT /note="Intravirion"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TRANSMEM 404..426
FT /note="Helical; Name=TM3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT TOPO_DOM 427..428
FT /note="Virion surface"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT REGION 2..204
FT /note="Pre-S"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT REGION 2..145
FT /note="Pre-S1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT REGION 110..144
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT REGION 146..204
FT /note="Pre-S2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT LIPID 2
FT /note="N-myristoyl glycine; by host"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT CARBOHYD 348
FT /note="N-linked (GlcNAc...) asparagine; by host"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_04075"
FT VAR_SEQ 1..206
FT /note="Missing (in isoform S)"
FT /evidence="ECO:0000305"
FT /id="VSP_031448"
FT VAR_SEQ 1..146
FT /note="Missing (in isoform M)"
FT /evidence="ECO:0000305"
FT /id="VSP_031449"
FT CARBOHYD P03144-2:3
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000250|UniProtKB:P03138"
SQ SEQUENCE 428 AA; 48383 MW; 5E84114BC33862D7 CRC64;
MGNNIKVTFD PNKLAAWWPT VGTYYTPTTT VTNPAIFKPG IYQTTSLKNP KNQQELDAIL
MTRYKEIDWD NWQGFPVNQR LPVSNNNPPS GQRAETFEIK SRPIIVPGIR DIPRGIVPPQ
TPSNRDQRRK PTPLTPPLRD THPHLTMKNQ TGHLQGFAEG LRALTTSDHH NSAYGDPFTT
LSPVVPTVST TLSPPLTIGD PVLSTEMSPS GLLGLLAGLQ VVYFLWTKIL TIAQSLDWWW
TSLSFPGGIP ECTGQNLQFQ TCKHLPTSCP PTCNGFRWMY LRRFIIYLLV LLLFLTFLLV
LLDWKGLLPV CPMMPATETT VNCRQCTISA QDTFTTPYCC CLKPTAGNCT CWPIPSSWAL
GSYLWEWALA RFSWLSLLVP LLQWLGGISL TVWLLLIWMI WFWGPVLMSI LPPFIPIFAL
FFLIWAYI
