Q91C37 (HBEAG_HBVA6) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
External core antigen

Alternative name(s):
HBeAg
Precore protein
p25

Gene names

Name:

C

Organism

Hepatitis B virus genotype A1 subtype adw2 (isolate South Africa/84/2001) (HBV-A) [Complete proteome]

Taxonomic identifier

489454 [NCBI]

Taxonomic lineage

Viruses › Retro-transcribing viruses › Hepadnaviridae › Orthohepadnavirus

Virus host

Pan troglodytes (Chimpanzee) [TaxID: 9598]
Homo sapiens (Human) [TaxID: 9606]

Protein attributes

Sequence length	214 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Inferred from homology

General annotation (Comments)

Function	May regulate immune response to the intracellular capsid in acting as a T cell tolerogen, by having an immunoregulatory effect which prevents destruction of infected cells by cytotoxic T cells. This immune regulation may predispose to chronicity during perinatal infections and prevent severe liver injury during adult infections By similarity.
Subunit structure	Homodimerizes By similarity.
Subcellular location	Secreted. Host nucleus By similarity.
Post-translational modification	Phosphorylated By similarity. Cleaved by host furin By similarity.
Sequence similarities	Belongs to the orthohepadnavirus precore antigen family.

Ontologies

Keywords
Biological process	Host-virus interaction Viral immunoevasion
Cellular component	Host nucleus Secreted
Coding sequence diversity	Alternative initiation
Domain	Repeat Signal
PTM	Disulfide bond
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	evasion by virus of host immune response Inferred from electronic annotation. Source: UniProtKB-KW pathogenesis Inferred from electronic annotation. Source: InterPro
Cellular component	host cell nucleus Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	structural molecule activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative initiation. [Align] [Select]

Isoform External core antigen (identifier: Q91C37-1)

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 Capsid protein (identifier: P0C695-1)

The sequence of this isoform can be found in the external entry P0C695.
Isoforms of the same protein are often annotated in two different entries if their sequences differ significantly.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 19	19	Potential
	Chain	20 – 185	166	External core antigen		PRO_0000324694
	Propeptide	186 – 214	29	By similarity		PRO_0000324695
Regions
	Repeat	186 – 192	7	1; half-length
	Repeat	193 – 200	8	2
	Repeat	201 – 208	8	3
	Region	186 – 208	23	3 X 8 AA repeats of S-P-R-R-R-R-S-Q
Sites
	Site	185 – 186	2	Cleavage; by host By similarity
Amino acid modifications
	Disulfide bond	77		Interchain By similarity
	Disulfide bond	90		Interchain By similarity

Sequences

	Sequence		Length	Mass (Da)
	Isoform External core antigen [UniParc]. Last modified December 1, 2001. Version 1. Checksum: FA9EEEF3FC8C30CB	FASTA	214	24,674
	10 20 30 40 50 60 MQLFHLCLII SCTCPTVQAS KLCLGWLWGM DIDPYKEFGA TVELLSFLPS DFFPSVRDLL 70 80 90 100 110 120 DTASALYREA LESPEHCSPH HTALRETILC WGELMTLATW VGNNLEDPAS RDLVVNYVNT 130 140 150 160 170 180 NMGLKIRQLL WFHISCLTFG RETVLEYLVS FGVWIRTPPA YRPPNAPILS TLPETTVVRR 190 200 210 RDRGRSPRRR TPSPRRRRSQ SPRRRRSQSR ESQC
	Isoform Capsid protein [UniParc]. See P0C695.		–	–

References

[1]	"Molecular analysis of hepatitis B virus genomes isolated from black African patients with fulminant hepatitis B." Owiredu W.K., Kramvis A., Kew M.C. J. Med. Virol. 65:485-492(2001) [PubMed: 11596083] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
+	Additional computationally mapped references.

Web resources

HepSEQ

Hepatitis virus B database

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF297625 Genomic DNA. Translation: AAK97202.1.
PIR	NKVLA3. C94409. S33686.
3D structure databases
ProteinModelPortal	Q91C37.
SMR	Q91C37. Positions 30-172.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR013195. Hepatitis_B_virus_capsid_N. IPR002006. Viral_capsid_core_Hepatitis. [Graphical view]
Pfam	PF08290. Hep_core_N. 1 hit. PF00906. Hepatitis_core. 1 hit. [Graphical view]
ProDom	PD000874. Vir_capsid_Znf-put_N_Hepatitis. 1 hit. [Graphical view] [Entries sharing at least one domain]
SUPFAM	SSF47852. Viral_capsid_core_Hepatitis. 1 hit.
ProtoNet	Search...

Entry information

Entry name

HBEAG_HBVA6

Accession

Primary (citable) accession number: Q91C37

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 18, 2008
Last sequence update:	December 1, 2001
Last modified:	September 21, 2011
This is version 40 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Viral Protein Annotation Program