Publication Date:
2000-06-17
Description:
Using fluorescence microscopy, we studied the catalysis by and folding of individual Tetrahymena thermophila ribozyme molecules. The dye-labeled and surface-immobilized ribozymes used were shown to be functionally indistinguishable from the unmodified free ribozyme in solution. A reversible local folding step in which a duplex docks and undocks from the ribozyme core was observed directly in single-molecule time trajectories, allowing the determination of the rate constants and characterization of the transition state. A rarely populated docked state, not measurable by ensemble methods, was observed. In the overall folding process, intermediate folding states and multiple folding pathways were observed. In addition to observing previously established folding pathways, a pathway with an observed folding rate constant of 1 per second was discovered. These results establish single-molecule fluorescence as a powerful tool for examining RNA folding.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhuang, X -- Bartley, L E -- Babcock, H P -- Russell, R -- Ha, T -- Herschlag, D -- Chu, S -- GM49423/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2000 Jun 16;288(5473):2048-51.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, Stanford University, Stanford, CA 94305-4060, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10856219" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Biotinylation
;
Carbocyanines
;
Catalysis
;
Fluorescent Dyes
;
Guanosine/metabolism
;
Kinetics
;
Microscopy, Fluorescence
;
Models, Molecular
;
*Nucleic Acid Conformation
;
Oligoribonucleotides/metabolism
;
RNA, Catalytic/*chemistry/*metabolism
;
RNA, Protozoan/*chemistry/metabolism
;
Tetrahymena thermophila
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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