Hepatitis delta virus ribozyme
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The hepatitis delta virus (HDV) ribozyme is a non-coding RNA found in the hepatitis delta virus that is necessary for viral replication and is the only known human virus that utilizes ribozyme activity to infect its host.[1] The ribozyme acts to process the RNA transcripts to unit lengths in a self-cleavage reaction during replication of the hepatitis delta virus, which is thought to propagate by a double rolling circle mechanism.[2][3] The ribozyme is active in vivo in the absence of any protein factors and was the fastest known naturally occurring self-cleaving RNA at the time of its discovery.[4]
Hepatitis delta virus ribozyme | |
---|---|
Identifiers | |
Symbol | HDV_ribozyme |
Rfam | RF00094 |
Other data | |
RNA type | Gene; ribozyme |
Domain(s) | Viruses |
SO | SO:0000374 |
PDB structures | PDBe |
The crystal structure of this ribozyme has been solved using X-ray crystallography and shows five helical segments connected by a double pseudoknot.[1]
In addition to the sense (genomic version), all HDV viruses also have an antigenomic version of the HDV ribozyme.[5] This version is not the exact complementary sequence but adopts the same structure as the sense (genomic) strand. The only "significant" differences between the two are a small bulge in P4 stem and a shorter J4/2 junction. Both the genomic and antigenomic ribozymes are necessary for replication.[2]