AC   MF_04076;
DC   Protein; auto
TR   HAMAP; MF_04076; -; 1; level=0
XX
Names: HBV_HBEAG
XX
case <FTTag:HBEAG>
ID   HBEAG
DE   RecName: Full=External core antigen;
DE   AltName: Full=HBeAg;
DE   AltName: Full=Precore protein;
DE   AltName: Full=p25;
DE   Flags: Precursor;
GN   Name=C;
else
ID   CAPSD
DE   RecName: Full=Capsid protein;
DE   AltName: Full=Core antigen;
DE   AltName: Full=Core protein;
DE   AltName: Full=HBcAg;
DE   AltName: Full=p21.5;
GN   Name=C;
end case
XX
case <FTTag:HBEAG>
CC   -!- FUNCTION: May regulate immune response to the intracellular capsid in
CC       acting as a T-cell tolerogen, by having an immunoregulatory effect
CC       which prevents destruction of infected cells by cytotoxic T-cells. This
CC       immune regulation may predispose to chronicity during perinatal
CC       infections and prevent severe liver injury during adult infections.
CC   -!- SUBUNIT: Homodimerizes.
CC   -!- SUBCELLULAR LOCATION: Secreted. Host nucleus.
CC   -!- PTM: Phosphorylated.
CC   -!- PTM: Cleaved by host furin.
CC   -!- SIMILARITY: Belongs to the orthohepadnavirus precore antigen family.
else
CC   -!- FUNCTION: Self assembles to form an icosahedral capsid. Most capsids
CC       appear to be large particles with an icosahedral symmetry of T=4 and
CC       consist of 240 copies of capsid protein, though a fraction forms
CC       smaller T=3 particles consisting of 180 capsid proteins. Entering
CC       capsids are transported along microtubules to the nucleus.
CC       Phosphorylation of the capsid is thought to induce exposure of nuclear
CC       localization signal in the C-terminal portion of the capsid protein
CC       that allows binding to the nuclear pore complex via the importin
CC       (karyopherin-) alpha and beta. Capsids are imported in intact form
CC       through the nuclear pore into the nuclear basket, where it probably
CC       binds NUP153. Only capsids that contain the mature viral genome can
CC       release the viral DNA and capsid protein into the nucleoplasm. Immature
CC       capsids get stuck in the basket. Capsids encapsulate the pre-genomic
CC       RNA and the P protein. Pre-genomic RNA is reverse-transcribed into DNA
CC       while the capsid is still in the cytoplasm. The capsid can then either
CC       be directed to the nucleus, providing more genomes for transcription,
CC       or bud through the endoplasmic reticulum to provide new virions.
CC   -!- SUBUNIT: Homodimerizes, then multimerizes. Interacts with cytosol
CC       exposed regions of viral L glycoprotein present in the reticulum-to-
CC       Golgi compartment. Interacts with human FLNB. Phosphorylated form
CC       interacts with host importin alpha; this interaction depends on the
CC       exposure of the NLS, which itself depends upon genome maturation and/or
CC       phosphorylation of the capsid protein. Interacts with host NUP153.
CC   -!- SUBCELLULAR LOCATION: Virion. Host cytoplasm.
CC   -!- PTM: Phosphorylated by host SRPK1, SRPK2, and maybe protein kinase C or
CC       GAPDH. Phosphorylation is critical for pregenomic RNA packaging.
CC       Protein kinase C phosphorylation is stimulated by HBx protein and may
CC       play a role in transport of the viral genome to the nucleus at the late
CC       step during the viral replication cycle.
CC   -!- SIMILARITY: Belongs to the orthohepadnavirus core antigen family.
end case
XX
DR   Pfam; PF08290; Hep_core_N; 0-1; trigger=no
DR   Pfam; PF00906; Hepatitis_core; 2-3; trigger=no
case <FTTag:HBEAG>
DR   General; Signal; -; 1; trigger=yes
end case
XX
case <FTTag:HBEAG>
KW   Disulfide bond
KW   Host nucleus
KW   Secreted
KW   Signal
KW   Viral immunoevasion
else
KW   Capsid protein
KW   Cytoplasmic inwards viral transport
KW   DNA-binding
KW   Host cytoplasm
KW   Microtubular inwards viral transport
KW   Phosphoprotein
KW   RNA-binding
KW   T=4 icosahedral capsid protein
KW   Viral penetration into host nucleus
KW   Virion
KW   Virus entry into host cell
end case
KW   Host-virus interaction
KW   Repeat
XX
case <FTTag:HBEAG>
GO   GO:0005576; C:extracellular region
GO   GO:0042025; C:host cell nucleus
GO   GO:0019049; P:virus-mediated perturbation of host defense response
else
GO   GO:0030430; C:host cell cytoplasm
GO   GO:0039619; C:T=4 icosahedral viral capsid
GO   GO:0003677; F:DNA binding
GO   GO:0003723; F:RNA binding
GO   GO:0075521; P:microtubule-dependent intracellular transport of viral material towards nucleus
GO   GO:0046718; P:viral entry into host cell
GO   GO:0075732; P:viral penetration into host nucleus
end case
GO   GO:0005198; F:structural molecule activity
XX
FT   From: HBEAG_HBVCJ (P0C767)
FT   REGION          25..27
FT                   /note="HBEAG"
FT   Tag: HBEAG; Condition: G-W-L
case <FTTag:HBEAG>
FT   SITE            183..184
FT                   /note="Cleavage; by host"
FT   Condition: R-S
FT   DISULFID        77
FT                   /note="Interchain"
FT   Condition: C
FT   DISULFID        90
FT                   /note="Interchain"
FT   Condition: C
else
FT   From: CAPSD_HBVCJ (Q76R61)
FT   REGION          177..183
FT                   /note="RNA binding"
FT   MOTIF           158..175
FT                   /note="Bipartite nuclear localization signal"
FT   MOD_RES         155
FT                   /note="Phosphoserine; by host"
FT   Condition: S
FT   MOD_RES         162
FT                   /note="Phosphoserine; by host"
FT   Condition: S
FT   MOD_RES         170
FT                   /note="Phosphoserine; by host"
FT   Condition: S
end case
XX
Size: 182-218;
Related: None;
Template: P0C767; Q76R61;
Scope:
 Viruses; Orthohepadnavirus
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: None
Comments: None
XX
# Revision 1.9 2023/12/15
//