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Descriptions are generated automatically from the ICTVdB database including links. Some descriptions are only very basic and links may point to documents that are not yet published on the Web.

00.030. Hepadnaviridae

Cite this publication as: ICTVdB Management (2006). 00.030. Hepadnaviridae. In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C. (Ed), Columbia University, New York, USA

Cite this site as: ICTVdB - The Universal Virus Database, version 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/

Table of Contents

Classification

This is a description of a vertebrate virus at the family level.

ICTVdB Virus Code: 00.030. Virus accession number: 00030FAM. Obsolete virus code: 30.; superceded accession number: 30000000.
NCBI Taxon Identifier NCBI Taxonomy ID: 10404.

Name, Synonyms and Lineage

Synonym(s): Hepatitis DNA virus.

Virion Properties

Morphology

Virions consist of an envelope and a nucleocapsid. Virus capsid is enveloped by a detergent sensitive lipoprotein (7 nm). Virions are spherical to pleomorphic (at times, filamentous forms occur and spherical structures that lack cores are common (HBsAg particles). Virions measure 40-48 nm in diameter, or 22 nm in diameter (for the HBsAg particles). The envelope has no surface projections. Capsid/nucleocapsid is round and exhibits icosahedral symmetry. The nucleocapsid is isometric and has a diameter of 30-35 nm. The capsid surface structure frequently reveals a regular pattern with distinctive features (concentric rings). The capsid consists of 180 capsomers.

Capsids can be penetrated by stain and some appear dark in the center. Incomplete particles are common.




















Electron micrograph of human Hepatitis B virus, Hepadnaviridae, by C. Büchen-Osmond.

Physicochemical and Physical Properties

Virions have a buoyant density in CsCl of 1.14-1.26 g cm-3.

Nucleic Acid

The genome is not segmented and contains a single molecule of circular. The genome is -RT. The genome is partially double-stranded DNA that forms a covalently closed circle (with 5' end of the full length minus strand which is linked to the viral DNA polymerase). The complete genome is 3020-3320 nucleotides long, or 1700-2800 nucleotides long (for the full and short length strand, respectively). The genome has a guanine + cytosine content of 48 %. The genome sequence has termini with cohesive ends (that match the uniquely located 5'-ends of the two strands which overlap by approximately 240 nucleotides and maintain the circular configuration of the DNA). The sequence has ENH an enhancer region and a direct repeat sequence (DR1 andDR2), or a U5-like sequence, a polyadenylated signal, and a putative glucocorticoid-responsive element; negative-sense or non-coding strand (complementary to the viral mRNA) is full-length (3.0-3.3 kb, positive sense strand (the viral mRNA) is variable in size and shorter than full-length. The double stranded genome has a nick at a unique site on full length negative strand opposite at a position 50 nucleotides, or 242 nucleotides downstream from the 5' end of the positive sense strand. The 5'-end of the negative-sense strand has a covalently attached terminal protein; positive-sense strand has a 5' capped oligoribonucleotide primer. The 3'-terminus has conserved nucleotide sequences; of 1 nucleotides in length.

GenBank records for nucleotide sequences; complete genome sequences.

Proteins

The viral genome encodes structural proteins and non-structural proteins located in the envelope.

Non-Structural Proteins: The virus codes for an RNA-dependent DNA polymerase.

Lipids

Lipids are present in significant amounts and are located in the envelope and empty particles (HBsAG components). The composition of viral lipids is known. The composition of viral lipids and host cell membranes are similar. The lipids are derived from a host membrane compartment intermediate between endoplasmatic reticulum membranes and Golgi membranes. Viral membranes include phospholipids, cholesterol, cholesterol esters, and triglycerides.

Translation: Replication involves a reverse transcription step.

Biological Properties

Natural Host

Virus infects during its life cycle a single type of vertebrate host.
Domain
Viral hosts belong to the Domain Eucarya.

Domain Eucarya
Kingdom Animalia.

Kingdom Animalia
Phylum Chordata.

Phylum Vertebrata
Subphylum Vertebrata.

Class Mammalia and Aves.

Class Aves Order Anseriformes; virus infects Anatidae.
Virus infects Anas (duck).

Class Mammalia Order Primates;
Family Hominidae.
Virus infects Homo sapiens (human).

Taxonomic Structure of the Family

00.030.0.01. Orthohepadnavirus
00.030.0.02. Avihepadnavirus.

Data Sources and Contributions

The description has been compiled from data in the ICTV Report presented by Howard C, Burrell CJ, Gerin JL, Gerlich WH, Gust ID, Koike K, Marion PL, Mason WS, Neurath AR, Newbold J, Robinson W, Schaller H, Tiollais P, Wen Y-M, Will H.

References

The following generic references are cited in the most recent ICTV Report.

PubMed References. Information about this virus have been posted on the web by a health support group (

Images

Taxon images: • EM by Cornelia Büchen-Osmond.



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DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia. ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses by Dr Cornelia Büchen-Osmond is written in DELTA. The virus descriptions in ICTVdB are coded by, or using data from experts in the field of virology or members ICTV. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations are automatically generated and formatted for display on the Web from the descriptions in DELTA-format. The description has been generated automatically from DELTA files. DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia.

ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses (ICTV) by Dr Cornelia Büchen-Osmond, is written in DELTA. The virus descriptions in ICTVdB are coded by ICTV members and experts, or by the ICTVdB Management using data provided by the experts, the literature or the latest ICTV Report. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations from the encoded descriptions are automatically generated and formatted for display on the Web.

Developer of the DELTA software: M. J. Dallwitz, T. Paine and E. Zurcher

ICTVdB and DELTA related References

Comments to ICTVdB Management
Last updated on 25 April 2006 by Cornelia Büchen-Osmond
Copyright © 2002    International Committee on Taxonomy of Viruses.    All rights reserved.


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