A Single-Molecule Study of RNA Catalysis and Folding

摘要: Using fluorescence microscopy, we studied the catalysis by and folding of individual Tetrahymena thermophila ribozyme molecules. The dye-labeled surface-immobilized ribozymes used were shown to be functionally indistinguishable from unmodified free in solution. A reversible local step which a duplex docks undocks core was observed directly single-molecule time trajectories, allowing determination rate constants characterization transition state. rarely populated docked state, not measurable ensemble methods, observed. In overall process, intermediate states multiple pathways addition observing previously established pathways, pathway with an constant 1 per second discovered. These results establish as powerful tool for examining RNA folding.