A Transition State Analogue for an RNA-Editing Reaction

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• 作者：Brittany L. Haudenschild ; Olena Maydanovych ; Eduardo A. Vé ; liz ; Mark R. Macbeth ; Brenda L. Bass ; and Peter A. Beal
• 刊名：Journal of the American Chemical Society
• 出版年：2004
• 出版时间：September 15, 2004
• 年：2004
• 卷：126
• 期：36
• 页码：11213 - 11219
• 全文大小：116K
• 年卷期：v.126,no.36(September 15, 2004)
• ISSN：1520-5126

文摘

Deamination at C6 of adenosine in RNA catalyzed by the ADAR enzymes generates inosine atthe corresponding position. Because inosine is decoded as guanosine during translation, this modificationcan lead to codon changes in messenger RNA. Hydration of 8-azanebularine across the C6-N1 doublebond generates an excellent mimic of the transition state proposed for the hydrolytic deamination reactioncatalyzed by ADARs. Here, we report the synthesis of a phosphoramidite of 8-azanebularine and its usein the preparation of RNAs mimicking the secondary structure found at a known editing site in the glutamatereceptor B subunit pre-mRNA. The binding properties of analogue-containing RNAs indicate that a tightbinding ligand for an ADAR can be generated by incorporation of 8-azanebularine. The observed high-affinity binding is dependent on a functional active site, the presence of one, but not the other, of ADAR2'stwo double-stranded RNA-binding motifs (dsRBMs), and the correct placement of the nucleoside analogueinto the sequence/structural context of a known editing site. These results advance our understanding ofsubstrate recognition during ADAR-catalyzed RNA editing and are important for structural studies of ADAR·RNA complexes.