Self-cleavage of virusoid RNA is performed by the proposed 55-nucleotide active site.
Virusoids are circular single-stranded RNAs dependent on plant viruses for replication and encapsidation. Recently, we showed that an in vitro-synthesized RNA containing 273 nucleotides of the 324-nucleotide virusoid of lucerne transient streak virus self-cleaves at a unique site. The reaction requires heating and snap cooling of the RNA and the subsequent addition of magnesium ions. Here, we test the 55-nucleotide, hammerhead-shaped, structural model proposed for the active site by preparing RNAs with both 5' and 3' terminal deletions. Results indicate that the hammerhead structure is sufficient and necessary for self-cleavage, that certain sequences prevent the formation of the hammerhead structure in the native virusoid RNA, and that an RNA molecule containing only 52 nucleotides is capable of an RNA-mediated reaction.
D001483:Base Sequence; D009690:Nucleic Acid Conformation; D010942:Plant Viruses / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional; D012328:RNA Viruses / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D013329:Structure-Activity Relationship
D012367:RNA, Viral