Optimal self-cleavage activity of the hepatitis delta virus RNA is dependent on a homopurine base pair in the ribozyme core.

Journal Article (Journal Article)

A non-Watson-Crick G.G interaction within the core region of the hepatitis delta virus (HDV) antigenomic ribozyme is required for optimal rates of self-cleavage activity. Base substitutions for either one or both G's revealed that full activity was obtained only when both G's were replaced with A's. At those positions, substitutions that generate potential Watson-Crick, G.U, heteropurine, or homopyrimidine combinations resulted in dramatically lower cleavage activity. A homopurine symmetric base pair, of the same type identified in the high-affinity binding site of the HIV RRE, is most consistent with this data. Additional features shared between the antigenomic ribozyme and the Rev binding site in the vicinity of the homopurine pairs suggest some structural similarity for this region of the two RNAs and a possible motif associated with this homopurine interaction. Evidence for a homopurine pair at the equivalent position in a modified form of the HDV genomic ribozyme was also found. With the postulated symmetric pairing scheme, large distortions in the nucleotide conformation, the sugar-phosphate backbone, or both would be necessary to accommodate this interaction at the end of a helix; we hypothesize that this distortion is critical to the structure of the active site of the ribozyme and it is stabilized by the homopurine base pair.

Full Text

Duke Authors

Cited Authors

  • Been, MD; Perrotta, AT

Published Date

  • December 1995

Published In

Volume / Issue

  • 1 / 10

Start / End Page

  • 1061 - 1070

PubMed ID

  • 8595561

Pubmed Central ID

  • PMC1369332

International Standard Serial Number (ISSN)

  • 1355-8382


  • eng

Conference Location

  • United States