Orthohepadnavirus

Orthohepadnavirus is a genus of viruses, in the family Hepadnaviridae. Humans and other mammals serve as natural hosts. There are 12 species in this genus. Diseases associated with this genus include: hepatitis, hepatocellular carcinoma (chronic infections), and cirrhosis.

Taxonomy
The genus contains the following species:
 * Capuchin monkey hepatitis B virus
 * Chinese shrew hepatitis B virus
 * Domestic cat hepatitis B virus
 * Ground squirrel hepatitis virus
 * Hepatitis B virus
 * Long-fingered bat hepatitis B virus
 * Pomona bat hepatitis B virus
 * Roundleaf bat hepatitis B virus
 * Taï Forest hepadnavirus
 * Tent-making bat hepatitis B virus
 * Woodchuck hepatitis virus
 * Woolly monkey hepatitis B virus

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.

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.