Orthohepadnavirus

{{Short description|Genus of viruses}}

{{Use dmy dates|date=April 2017}}

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| image = Hepatitis B virus 1.jpg

| image_alt = TEM micrograph showing Hepatitis B virus virions

| image_caption = TEM micrograph showing Hepatitis B virus virions

| taxon = Orthohepadnavirus

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| subdivision_ranks = Species

| subdivision = See text

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Orthohepadnavirus is a genus of viruses, in the family Hepadnaviridae.{{cite web |title=ICTV Report Hepadnaviridae |url=http://www.ictv.global/report/hepadnaviridae}} Humans and other mammals serve as natural hosts. There are 19 species in this genus. Diseases associated with this genus include: hepatitis, hepatocellular carcinoma (chronic infections), and cirrhosis.{{cite web|title=Viral Zone|url=http://viralzone.expasy.org/all_by_species/101.html|publisher=ExPASy|accessdate=15 June 2015}}

Taxonomy

The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species:{{cite web|title=Virus Taxonomy: 2024 Release|url=https://ictv.global/taxonomy|publisher=International Committee on Taxonomy of Viruses|access-date=22 March 2025}}

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Structure

Viruses in the genus Orthohepadnavirus are enveloped, with spherical geometries, and T=4 symmetry. The diameter is around 42 nm. Genomes are circular, around 3.2kb in length. The genome codes for 7 proteins.

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GenusStructure || SymmetryCapsidGenomic arrangementGenomic segmentation
OrthohepadnavirusIcosahedralT=4Non-envelopedCircularMonopartite

Life cycle

Viral replication is nucleo-cytoplasmic. Replication follows the dsDNA(RT) replication model. DNA-templated transcription, specifically dsDNA(RT) transcription, with some alternative splicing mechanism is the method of transcription. Translation takes place by leaky scanning. The virus exits the host cell by budding, and nuclear pore export. Human and mammals serve as the natural host. Transmission routes are sexual, blood, and contact.

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GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
OrthohepadnavirusHumans; mammalsHepatocytesCell receptor endocytosisBuddingNucleusCytoplasmVertical: parental; sex; blood

References

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