Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.
The hepatitis C virus (HCV) is a small, enveloped, positive-sense single-stranded RNA virus of the family Flaviviridae. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer and lymphomas in humans.
Rubella virus (RuV) is the pathogenic agent of the disease rubella, transmitted only between humans via the respiratory route, and is the main cause of congenital rubella syndrome when infection occurs during the first weeks of pregnancy.
VPg is a protein that is covalently attached to the 5′ end of positive strand viral RNA and acts as a primer during RNA synthesis in a variety of virus families including Picornaviridae, Potyviridae and Caliciviridae. There are some studies showing that a possible VPg protein is also present in astroviridae, however, experimental evidence for this has not yet been provided and requires further study. The primer activity of VPg occurs when the protein becomes uridylated, providing a free hydroxyl that can be extended by the virally encoded RNA-dependent RNA polymerase. For some virus families, VPg also has a role in translation initiation by acting like a 5' mRNA cap.
The Hepatitis C stem-loop IV is part of a putative RNA element found in the NS5B coding region. This element along with stem-loop VII, is important for colony formation, though its exact function and mechanism are unknown.
The hepatitis C virus 3′X element is an RNA element which contains three stem-loop structures that are essential for replication.
The Hepatitis C virus (HCV) cis-acting replication element (CRE) is an RNA element which is found in the coding region of the RNA-dependent RNA polymerase NS5B. Mutations in this family have been found to cause a blockage in RNA replication and it is thought that both the primary sequence and the structure of this element are crucial for HCV RNA replication.
The retroviral psi packaging element, also known as the Ψ RNA packaging signal, is a cis-acting RNA element identified in the genomes of the retroviruses Human immunodeficiency virus (HIV) and Simian immunodeficiency virus (SIV). It is involved in regulating the essential process of packaging the retroviral RNA genome into the viral capsid during replication. The final virion contains a dimer of two identical unspliced copies of the viral genome.
The Rubella virus 3′ cis-acting element RNA family represents a cis-acting element found at the 3′ UTR in the rubella virus. This family contains three conserved step loop structures. Calreticulin (CAL), which is known to bind calcium in most eukaryotic cells, is able to specifically bind to the first stem loop of this RNA. CAL binding is thought to be related to viral pathogenesis and in particular arthritis which occurs frequently in rubella infections in adults and is independent of viral viability. All stem loop structures are thought to be important for efficient viral replication and deletion of stem loop three is known to be lethal.
Tombusvirus 5′ UTR is an important cis-regulatory region of the Tombus virus genome.
Hepatitis C alternative reading frame stem-loop is a conserved secondary structure motif identified in the RNA genome of the Hepatitis C virus (HCV) which is proposed to have an important role in regulating translation and repression of the viral genome.
The HBV RNA encapsidation signal epsilon is an element essential for HBV virus replication.
The Hepatitis B virus PRE stem-loop alpha is an RNA structure that is shown to play a role in nuclear export of HBV mRNAs.
Hepatitis B virus (HBV) is a partially double-stranded DNA virus, a species of the genus Orthohepadnavirus and a member of the Hepadnaviridae family of viruses. This virus causes the disease hepatitis B.
Cis-acting replication elements bring together the 5′ and 3′ ends during replication of positive-sense single-stranded RNA viruses and double-stranded RNA viruses.
In molecular biology, the Hepatitis A virus cis-acting replication element (CRE) is an RNA element which is found in the coding region of the RNA-dependent RNA polymerase in Hepatitis A virus (HAV). It is larger than the CREs found in related Picornavirus species, but is thought to be functionally similar. It is thought to be involved in uridylylation of VPg.
In molecular biology, the Avian encephalitis virus cis-acting replication element (CRE) is an s an RNA element which is found in the coding region of the RNA-dependent RNA polymerase in Avian encephalitis virus (AEV). It is structurally similar to the Hepatitis A virus cis-acting replication element.
Non-structural protein 5B (NS5B) inhibitors are a class of direct-acting antivirals widely used in the treatment of chronic hepatitis C. Depending on site of action and chemical composition, NS5B inhibitors may be categorized into three classes—nucleoside active site inhibitors (NIs), non-nucleoside allosteric inhibitors, and pyrophosphate analogues. Subsequently, all three classes are then subclassified. All inhibit RNA synthesis by NS5B but at different stages/sites resulting in inability of viral RNA replication. Expression of direct-acting NS5B inhibitors does not takes place cells that are not infected by hepatitis C virus, which seems to be beneficial for this class of drugs.
Flavivirus 5' UTR are untranslated regions in the genome of viruses in the genus Flavivirus.
