The secondary structures proposed for the cis-acting hepatitis delta virus (HDV) ribozymes contain four duplex regions, three sequences joining the duplexes and two hairpin loops. The core and active site of the ribozyme could be formed by portions of the joining sequences, J1/4 and J4/2, together with one of the hairpin loops, L3. To establish the core region and define essential bases within ...

In elucidating function of two important single-stranded regions [SSrA (726-731 nt) and SSrB (762-766 nt)] derived mainly from three secondary structure models in genomic hepatitis delta virus (HDV) ribozyme possessing self-cleavage activity, we have constructed several random mutants at those two regions on the HDV88 molecule (683-770 nt) by oligonucleotide-directed mutagenesis. When self-clea...

Replication of the genome of hepatitis delta virus (HDV) requires RNA-directed RNA synthesis using a host polymerase(s). This manuscript reviews the relevant published evidence. It also provides two new studies, both of which made use of transiently transfected Huh7 cells undergoing HDV RNA-directed RNA synthesis. For the first study, RNA transcription inhibitors were added to the transfected c...

An RNA fold is the result of packing together two or more coaxial helical stacks. To date, four RNA folds have been determined at near-atomic resolution by X-ray crystallography: transfer RNA, the hammerhead ribozyme, the P4-P6 domain of the Tetrahymena group I intron, and the hepatitis delta virus ribozyme. All four folds result in RNAs that are considerably more compact than isolated A-form d...

BACKGROUND Hepatitis B virus (HBV) has been reported as a coinfection with hepatitis C virus (HCV), hepatitis D virus (HDV), cytomegalovirus (CMV), and human immunodeficiency virus (HIV). CASE REPORT A 34-year-old female presented to our clinic with epigastric pain and severe acute hepatitis manifested as jaundice associated with hyperbilirubinemia, elevated transaminases, and coagulopathy. The...

Serum 25-hydroxy-vitamin D (25-OHD) concentrations were measured in 49 patients with hepatobiliary disease in infancy. Low mean values were found in groups of patients with biliary atresia, neonatal hepatitis, choledochal cyst, and chronic intrahepatic cholestatic syndrome. In the group of patients with surgically repaired biliary atresia, the mean value did not differ from normal. Parenteral v...

In models of the replication of human hepatitis delta virus (HDV) RNA, it is generally assumed that circular RNAs are the only templates. However, noncircular HDV RNAs are also produced during replication, and it is known that replication can be initiated by transfection with noncircular RNAs. Therefore, strategies were devised to determine the relative ability of different HDV RNA species to i...

The past few years have seen exciting advances in understanding the structure and function of catalytic RNA. Crystal structures of several ribozymes have provided detailed insight into the folds of RNA molecules. Models of other biologically important RNAs have been constructed based on structural, phylogenetic, and biochemical data. However, many questions regarding the catalytic mechanisms of...