Hepatitis B virus, capsid N-terminal (IPR013195)

Short name: Hepatitis_B_virus_capsid_N

Overlapping homologous superfamilies


Domain relationships



This entry represent a short region found at the N terminus of some viral capsid (HBcAg) proteins from various Hepatitis B virus (HBV), which is a major human pathogen. The conservation of four Cys residues suggests that this region acts as a zinc binding domain.

Hepatitis virus is composed of an outer envelope of host-derived lipid containing the surface proteins, and an inner protein capsid that contains genomic DNA. The capsid is composed of a single polypeptide, HBcAg, also known as the core antigen. The capsid has a 5-helical fold, where two long helices form a hairpin that dimerises into a 4-helical bundle [PMID: 10394365]; this fold is unusual for icosahedral viruses. The monomer fold is stabilised by a hydrophobic core that is highly conserved among human viral variants. The capsid is assembled from dimers via interactions involving a highly conserved arginine-rich region near the C terminus. This viral capsid acts as a core antigen, the major immunodominant region lying at the tips of the alpha-helical hairpins that form spikes on the capsid surface.

GO terms

Biological Process

GO:0009405 pathogenesis

Molecular Function

GO:0005198 structural molecule activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
  • PD000874 (Vir_capsid_Znf-put_N_Hepatitis)