FOLDING OF SELF-CLEAVING SMALL RIBOZYMES DURINGTRANSCRIPTION Ribozymes are known as molecular scissors. Folding during transcription in vitro for the hairpin and delta ribozymes focused on the effect of upstream and downstream regions that could interfere with the folding of the catalytically active structure.
In case of the hairpin ribozyme, complementary insertions of an interfering stem-loop upstream of the ribozyme inhibited folding pattern more severely than did an insertion downstream of the ribozyme. In the case of the delta ribozyme, folding during transcription was inhibited strongly by the presence of a downstream portion of the viroid RNA. Folding of the delta ribozyme was more efficient upon decreasing the transcription speed.