Mispaired P3 region in the hierarchical folding pathway of the Tetrahymena ribozyme

✍ Scribed by Yasushi Ohki; Yoshiya Ikawa; Hideaki Shiraishi; Tan Inoue

• Book ID: 104460434
• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 630 KB
• Volume: 7
• Category: Article
• ISSN: 1356-9597
• DOI: 10.1046/j.1365-2443.2002.00567.x

✦ Synopsis

Abstract

Background: The Tetrahymena group I ribozyme folds into a complex three‐dimensional structure for performing catalytic reactions. The catalysis depends on its catalytic core consisting of two helical domains, P4–P6 and P3–P7, connected by single stranded regions. In the folding process, most of this ribozyme folds in a hierarchical manner in which a kinetically stable intermediate determines the overall folding rate.

Results: Although the nature of this intermediate has not yet been elucidated, a mispaired P3 stem (alt‐P3) appears a likely candidate. To examine the effects of the alt‐P3 structure on the kinetic and thermodynamic properties of the active structure of the ribozyme or its P3–P7 domain formation, we prepared and analysed variant ribozymes in which relative stabilities of the original P3 and alt‐P3 structure were altered systematically.

Conclusion: The results indicate that the alt‐P3 structure is not the major rate‐limiting factor in the folding process.