Folding and catalysis by the hairpin ribozyme

FEBS Letters

Lilley, David M.J¹ 

[1] CRC Nucleic Acid Structure Research Group, Department of Biochemistry, The University of Dundee, Dundee DD1 4HN, UK

关键词: RNA structure;    Transesterification reaction;    RNA-mediated catalysis;    Metal ion;   

DOI  :  10.1016/S0014-5793(99)00544-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The hairpin ribozyme undergoes a site-specific transesterification cleavage of the phosphodiester backbone. The natural form of the ribozyme is a four-way helical junction, where two arms contain unpaired loops. This folds by pairwise coaxial stacking of helical arms, and a rotation into an antiparallel conformation in which there is close association between the loops. This probably generates the local conformation required to facilitate the trajectory into an in-line S_N2 transition state. Folding is induced by the cooperative binding of at least two divalent metal ions, which are probably distributed between the junction and the loop-loop interface. The junction forms the structural scaffold on which the geometry of the ribozyme is built, and structural perturbation of the junction leads to impaired catalytic activity.

【 授权许可】

Unknown