title: Bioinformatic analysis of the hepadnavirus e-antigen and its precursor identifies remarkable sequence conservation in all orthohepadnaviruses.
abstract: The hepatitis B e-antigen (HBeAg) is a non-particulate secretory protein expressed by all viruses within the family Hepadnaviridae. It is not essential for viral assembly or replication but is important for establishment of persistent infection in vivo. Although the exact mechanism(s) by which the HBeAg manifests chronicity are unclear, the HBeAg elicits both humoral and cell-mediated immunity, down-regulates the innate immune response to infection, as well as functioning as a T cell tolerogen and regulating the immune response to the intracellular nucleocapsid. A bioinformatics approach was used to show that the HBeAg and precursory genetic codes share remarkable sequence conservation in all mammalian-infecting hepadnaviruses, irrespective of host, genotype, or geographic origin. Whilst much of this sequence conservation was within key immunomodulatory epitopes, highest conservation was observed at the unique HBeAg N-terminus, suggesting this sequence in particular may play an important role in HBeAg function.
authors: Victorian Infectious Diseases Reference Laboratory, North Melbourne, Australia. Peter.Revill@mh.org.au
authors: Peter
authors: P
authors: Revill
authors: Lilly
authors: L
authors: Yuen
authors: Renae
authors: R
authors: Walsh
authors: Marie
authors: M
authors: Perrault
authors: Stephen
authors: S
authors: Locarnini
authors: Anna
authors: A
authors: Kramvis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019295:Computational Biology; D017124:Conserved Sequence; D005838:Genotype; D015613:Hepadnaviridae / Q000235:genetics / Q000276:immunology*; D006513:Hepatitis B e Antigens / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D017918:Orthohepadnavirus / Q000235:genetics / Q000276:immunology; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D006513:Hepatitis B e Antigens; D011498:Protein Precursors