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Q9WKC4 (HBSAG_HBVGO) Reviewed, UniProtKB/Swiss-Prot

Last modified May 31, 2011. Version 44. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
Large envelope protein
Alternative name(s):
L glycoprotein
L-HBsAg
Short name=LHB
Large S protein
Large surface protein
Major surface antigen
Gene names
Name:S
OrganismGorilla hepatitis B virus (isolate Cameroon/gor97) (HBVgor) [Complete proteome]
Taxonomic identifier489546 [NCBI]
Taxonomic lineageViruses › Retro-transcribing viruses › Hepadnaviridae › Orthohepadnavirus
Virus hostGorilla gorilla (western gorilla) [TaxID: 9593]

Protein attributes

Sequence length389 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceInferred from homology

General annotation (Comments)

Function

The large envelope protein exists in two topological conformations, one which is termed 'external' or Le-HBsAg and the other 'internal' or Li-HBsAg. In its external conformation the protein attaches the virus to cell receptors and thereby initiating infection. This interaction determines the species specificity and liver tropism. The large envelope protein probably also assumes fusion between virion and host membranes. In its internal conformation the protein plays a role in virion morphogenesis and mediates the contact with the nucleocapsid like a matrix protein By similarity.

The middle envelope protein plays an important role in the budding of the virion. It is involved in the induction of budding in a nucleocapsid independent way. In this process the majority of envelope proteins bud to form subviral lipoprotein particles of 22 nm of diameter that do not contain a nucleocapsid By similarity.

Subunit structure

Li-HBsAg interacts with capsid protein and with HDV Large delta antigen. Isoform M associates with host chaperone CANX through its pre-S2 N glycan. This association may be essential for M proper secretion By similarity.

Subcellular location

Virion membrane By similarity.

Domain

The large envelope protein is synthesized with the pre-S region at the cytosolic side of the endoplasmic reticulum and, hence will be within the virion after budding. Therefore the pre-S region is not N-glycosylated. Later a post-translational translocation of N-terminal pre-S and TM1 domains occur in about 50% of proteins at the virion surface. These molecules change their topology by an unknown mechanism, resulting in exposure of pre-S region at virion surface. For isoform M in contrast, the pre-S2 region is translocated cotranslationally to the endoplasmic reticulum lumen and is N-glycosylated.

Post-translational modification

Isoform M is N-terminaly acetylated at a ratio of 90%, and N-glycosylated at the pre-S2 region By similarity.

Myristoylated By similarity.

Sequence similarities

Belongs to the orthohepadnavirus major surface antigen family.

Alternative products

This entry describes 3 isoforms produced by alternative splicing and alternative initiation. [Align] [Select]
Isoform L (identifier: Q9WKC4-1)

Also known as: Large envelope protein; LHB; L-HBsAg;

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
Isoform M (identifier: Q9WKC4-2)

Also known as: Middle envelope protein; MHB; M-HBsAg;

The sequence of this isoform differs from the canonical sequence as follows:
     1-108: Missing.
Isoform S (identifier: Q9WKC4-3)

Also known as: Small envelope protein; SHB; S-HBsAg;

The sequence of this isoform differs from the canonical sequence as follows:
     1-163: Missing.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Initiator methionine11Removed; by host By similarity
Chain2 – 389388Large envelope protein
PRO_0000319292

Regions

Topological domain2 – 242241Cytoplasmic; in internal conformation Potential
Topological domain2 – 170169Extracellular; in external conformation Potential
Transmembrane171 – 19121Helical; Note=In external conformation; Potential
Topological domain192 – 24251Cytoplasmic; in external conformation Potential
Transmembrane243 – 26321Helical; Potential
Topological domain264 – 33774Extracellular Potential
Transmembrane338 – 35821Helical; Potential
Topological domain359 – 3646Cytoplasmic Potential
Transmembrane365 – 38723Helical; Potential
Topological domain388 – 3892Extracellular Potential
Region2 – 163162Pre-S By similarity
Region2 – 108107Pre-S1 By similarity
Region109 – 16355Pre-S2 By similarity

Amino acid modifications

Modified residue1091N-acetylmethionine; by host; in isoform M By similarity
Lipidation21N-myristoyl glycine; by host By similarity
Glycosylation1121N-linked (GlcNAc...); by host; in isoform M By similarity
Glycosylation3091N-linked (GlcNAc...); by host By similarity

Natural variations

Alternative sequence1 – 163163Missing in isoform S.
VSP_031466
Alternative sequence1 – 108108Missing in isoform M.
VSP_031467

Sequences

Sequence LengthMass (Da)Tools
Isoform L (Large envelope protein) (LHB) (L-HBsAg) [UniParc].

Last modified November 1, 1999. Version 1.
Checksum: A532CE31D39471FA

FASTA38942,671
        10         20         30         40         50         60 
MGQNLSTSNP LGFFPEHQLD PAFKANTNNP DWDFNPNKDN WPKANEVGVG AFGPGLTPPH 

        70         80         90        100        110        120 
GGLLGWSPQA QGIITTVPAN PPPASTNRQS GRKPTPISPP LRDTHPQAMH WNSTTFHQAL 

       130        140        150        160        170        180 
QDPRVRGLYF PAGGSSSGTA YPVPDTASHI SSIFSRTGDP APNMESITSG FLGPLLVLQA 

       190        200        210        220        230        240 
GFFLLTKILT IPQSLDSWWT SLNFLGGAPV CLGQNSQSPT SNHSPTSCPP ICPGYRWMCL 

       250        260        270        280        290        300 
RRFIIFLFIL LLCLIFLLVL LDYQGMLPVC PLIPGSTTTS TGPCKTCTTT AQGTSLYPSC 

       310        320        330        340        350        360 
CCTKPSDGNC TCIPIPSSWA FAKFLWEWAS VRFSWLSLLA PFVQWFAGLS PTVWLSVIWM 

       370        380 
MWYWGPNLYN ILSPFIPLLP IFFCLWVYI

« Hide

Isoform M (Middle envelope protein) (MHB) (M-HBsAg) [UniParc].

Checksum: 87EA0034DC2149F4
Show »

FASTA28131,194
Isoform S (Small envelope protein) (SHB) (S-HBsAg) [UniParc].

Checksum: 1DC79F589FAA7DF8
Show »

FASTA22625,322

References

[1]"Molecular epidemiology of hepatitis B virus variants in nonhuman primates."
Grethe S., Heckel J.O., Rietschel W., Hufert F.T.
J. Virol. 74:5377-5381(2000) [PubMed: 10799618] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]"Functions of the large hepatitis B virus surface protein in viral particle morphogenesis."
Bruss V., Gerhardt E., Vieluf K., Wunderlich G.
Intervirology 39:23-31(1996) [PubMed: 8957666] [Abstract]
Cited for: REVIEW.
[3]"Role of glycan processing in hepatitis B virus envelope protein trafficking."
Block T.M., Lu X., Mehta A., Park J., Blumberg B.S., Dwek R.
Adv. Exp. Med. Biol. 435:207-216(1998) [PubMed: 9498079] [Abstract]
Cited for: REVIEW.
[4]"Envelopment of the hepatitis B virus nucleocapsid."
Bruss V.
Virus Res. 106:199-209(2004) [PubMed: 15567498] [Abstract]
Cited for: REVIEW.
[5]"Hepatitis B virus pre-S mutants, endoplasmic reticulum stress and hepatocarcinogenesis."
Wang H.C., Huang W., Lai M.D., Su I.J.
Cancer Sci. 97:683-688(2006) [PubMed: 16863502] [Abstract]
Cited for: REVIEW.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		AJ131567 Genomic DNA. Translation: CAA10423.1.
PIRJQ2088.

3D structure databases

ModBaseSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

InterProIPR000349. Hepvir_surfAg.
[Graphical view]
PfamPF00695. vMSA. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameHBSAG_HBVGO
AccessionPrimary (citable) accession number: Q9WKC4
Entry history
Integrated into UniProtKB/Swiss-Prot: February 26, 2008
Last sequence update: November 1, 1999
Last modified: May 31, 2011
This is version 44 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

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