P0C573 (HBEAG_HBVD3) 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 D subtype ayw (isolate France/Tiollais/1979) (HBV-D) [Complete proteome]

Taxonomic identifier

490133 [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	212 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

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.
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: P0C573-1)

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: P03146-1)

The sequence of this isoform can be found in the external entry P03146.
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 – 183	164	External core antigen		PRO_0000324724
	Propeptide	184 – 212	29			PRO_0000324725
Regions
	Repeat	184 – 190	7	1; half-length
	Repeat	191 – 198	8	2
	Repeat	199 – 206	8	3
	Region	184 – 206	23	3 X 8 AA repeats of S-P-R-R-R-R-S-Q
Sites
	Site	183 – 184	2	Cleavage; by host
Amino acid modifications
	Disulfide bond	77		Interchain By similarity
	Disulfide bond	90		Interchain By similarity
Experimental info
	Mutagenesis	180	1	R → G: Complete loss of cleavage. Ref.3
	Mutagenesis	183	1	R → G: Complete loss of cleavage. Ref.3
	Mutagenesis	186	1	R → G: No effect on cleavage. Ref.3
	Mutagenesis	188	1	R → G: No effect on cleavage. Ref.3
	Mutagenesis	193	1	R → G: No effect on cleavage. Ref.3
	Mutagenesis	196	1	R → G: No effect on cleavage. Ref.3
	Mutagenesis	201	1	R → G: No effect on cleavage. Ref.3
	Mutagenesis	204	1	R → G: No effect on cleavage. Ref.3

Sequences

	Sequence		Length	Mass (Da)
	Isoform External core antigen [UniParc]. Last modified March 18, 2008. Version 1. Checksum: D3016A4E8B05A1B8	FASTA	212	24,350
	10 20 30 40 50 60 MQLFHLCLII SCSCPTVQAS KLCLGWLWGM DIDPYKEFGA TVELLSFLPS DFFPSVRDLL 70 80 90 100 110 120 DTASALYREA LESPEHCSPH HTALRQAILC WGELMTLATW VGVNLEDPAS RDLVVSYVNT 130 140 150 160 170 180 NMGLKFRQLL WFHISCLTFG RETVIEYLVS FGVWIRTPPA YRPPNAPILS TLPETTVVRR 190 200 210 RGRSPRRRTP SPRRRRSQSP RRRRSQSRES QC
	Isoform Capsid protein [UniParc]. See P03146.		–	–

References

[1]	"Nucleotide sequence of the hepatitis B virus genome (subtype ayw) cloned in E. coli." Galibert F., Mandart E., Fitoussi F., Tiollais P., Charnay P. Nature 281:646-650(1979) [PubMed: 399327] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Subtype ayw variant of hepatitis B virus. DNA primary structure analysis." Bichko V., Pushko P., Dreilina D., Pumpen P., Gren E.Y. FEBS Lett. 185:208-212(1985) [PubMed: 3996597] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: Latvia.
[3]	"A structural model for duck hepatitis B virus core protein derived by extensive mutagenesis." Nassal M., Leifer I., Wingert I., Dallmeier K., Prinz S., Vorreiter J. J. Virol. 81:13218-13229(2007) [PubMed: 17881438] [Abstract] Cited for: CLEAVAGE BY HOST FURIN, MUTAGENESIS OF ARG-180; ARG-183; ARG-186; ARG-188; ARG-193; ARG-196; ARG-201 AND ARG-204.

Web resources

HepSEQ

Hepatitis virus B database

Cross-references

Sequence databases
EMBL GenBank DDBJ	V01460 Genomic DNA. No translation available. X02496 Genomic DNA. No translation available.
3D structure databases
ProteinModelPortal	P0C573.
SMR	P0C573. 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_HBVD3

Accession

Primary (citable) accession number: P0C573

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 18, 2008
Last sequence update:	March 18, 2008
Last modified:	September 21, 2011
This is version 17 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Viral Protein Annotation Program