期刊
RNA
卷 12, 期 4, 页码 607-619出版社
COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT
DOI: 10.1261/rna.2266506
关键词
ribozyme; riboswitch; glmS; glucosamine; 6-phosphate; metal ions; pseudoknot
The glmS ribozyme is a riboswitch class that occurs in certain Gram-positive bacteria, where it resides within mRNAs encoding glucosamine 6-phosphate synthase. Members of this self-cleaving ribozyme class rapidly catalyze RNA transesterification upon binding GlcN6P, and genetic evidence suggests that this cleavage event is important for down-regulating GlmS protein expression. In this report, we present a refined secondary structure model of the glmS ribozyme and determine the importance of a conserved pseudoknot structure for optimal ribozyme function. Analyses of deletion constructs demonstrate that the pseudoknot, together with other structural elements, permits the ribozyme to achieve maximum rate constants for RNA cleavage at physiologically relevant Mg2+ concentrations. In addition, we show that substantial rate enhancements are supported by an exchange-inert cobalt (III) complex and by molar concentrations of monovalent ions. Our findings indicate that the glmS ribozyme forms a complex structure to employ catalytic strategies that do not require the direct participation of divalent metal ions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据