Processing of Potato Spindle Tuber Viroid RNAs in Yeast, a Nonconventional Host.

Potato spindle tuber viroid (PSTVd) is a circular, single-stranded, noncoding RNA plant pathogen that is a useful model for studying the processing of noncoding RNA in eukaryotes. Infective PSTVd circles are replicated via an asymmetric rolling circle mechanism to form linear multimeric RNAs. An endonuclease cleaves these into monomers, and a ligase seals these into mature circles.