Hepatitis delta virus ribozyme

The hepatitis delta virus (HDV) ribozyme is a non-coding RNA that is necessary for viral replication and is thought to be the only catalytic RNA known to be required for viability of a human pathogen. The ribozyme acts to process the RNA transcripts to unit lengths in a self-cleavage reaction. The ribozyme is found to be active in vivo in the absence of any protein factors and is the fastest known naturally occurring self-cleaving RNA.

The crystal structure of this ribozyme has been solved using X-ray crystallography and shows five helical segments connected by a double pseudoknot.