Figure 3.

The U3-based snorbozymes localize to the nucleolus. The intracellular location of the trans-acting ribozyme components was examined by fluorescent in situ hybridization microscopy. Catalytic and target RNA molecules were expressed in yeast cells from separate low copy plasmids (see text and Fig. 4). Yeast nucleoli were identified by using a probe specific for the box C/D U14 snoRNA. (A) Hybridization with a probe specific for the catalytic molecule. (B) Hybridization with a probe specific for an internal segment of the substrate RNA. This probe recognizes both the full-length target molecule and the cleaved and trimmed byproduct (see also Fig. 4). (C) Double hybridization with probes that recognize the catalytic molecule and the target and cleaved byproduct molecules. The labels in each image correspond to the RNA molecules identified.