Cofactor Binding Triggers Rapid Conformational Remodelling of the Active Site of a Methyltransferase Ribozyme.

IF 4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Journal of Biological Chemistry Pub Date : 2024-10-05 DOI:10.1016/j.jbc.2024.107863

Hengyi Jiang,Getong Liu,Yanqing Gao,Jianhua Gan,Dongrong Chen,Alastair I H Murchie

{"title":"Cofactor Binding Triggers Rapid Conformational Remodelling of the Active Site of a Methyltransferase Ribozyme.","authors":"Hengyi Jiang,Getong Liu,Yanqing Gao,Jianhua Gan,Dongrong Chen,Alastair I H Murchie","doi":"10.1016/j.jbc.2024.107863","DOIUrl":null,"url":null,"abstract":"The methyltransferase ribozyme SMRZ-1 utilizes S-adenosyl-methionine (SAM) and Cu (II) ions to methylate RNA. Comparison of the SAM bound and unbound RNA structures has shown a conformational change in the RNA. However, the contribution of specific interactions and the role of a pseudo-triplex motif in the catalytic centre on the methylation reaction is not completely understood. In this study, we have used atomic substitutions and mutational analysis to investigate the reaction specificity and the key interactions required for catalysis. Substitution of the fluorescent nucleotide 2-aminopurine within the active ribozyme enabled the conformational dynamics of the RNA upon co-factor binding to be explored using fluorescence spectroscopy. We show that fast co-factor binding (t1/2 ∼ 0.7 seconds) drives a conformational change in the RNA to facilitate methyl group transfer. The importance of stacking interactions at the pseudo-triplex motif and chelation of the Cu (II) ion were shown to be essential for SAM binding.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":null,"pages":null},"PeriodicalIF":4.0000,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Biological Chemistry","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.jbc.2024.107863","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

The methyltransferase ribozyme SMRZ-1 utilizes S-adenosyl-methionine (SAM) and Cu (II) ions to methylate RNA. Comparison of the SAM bound and unbound RNA structures has shown a conformational change in the RNA. However, the contribution of specific interactions and the role of a pseudo-triplex motif in the catalytic centre on the methylation reaction is not completely understood. In this study, we have used atomic substitutions and mutational analysis to investigate the reaction specificity and the key interactions required for catalysis. Substitution of the fluorescent nucleotide 2-aminopurine within the active ribozyme enabled the conformational dynamics of the RNA upon co-factor binding to be explored using fluorescence spectroscopy. We show that fast co-factor binding (t1/2 ∼ 0.7 seconds) drives a conformational change in the RNA to facilitate methyl group transfer. The importance of stacking interactions at the pseudo-triplex motif and chelation of the Cu (II) ion were shown to be essential for SAM binding.

查看原文本刊更多论文

辅因子结合引发甲基转移酶波形酶活性位点的快速构象重塑

甲基转移酶核糖核酶 SMRZ-1 利用 S-腺苷蛋氨酸（SAM）和 Cu (II) 离子使 RNA 甲基化。对 SAM 结合和未结合的 RNA 结构进行比较后发现，RNA 的构象发生了变化。然而，特定相互作用的贡献以及催化中心的伪三重基团对甲基化反应的作用还不完全清楚。在这项研究中，我们利用原子置换和突变分析来研究反应的特异性和催化所需的关键相互作用。在活性核糖酶中取代荧光核苷酸 2-aminopurine 可以利用荧光光谱探索 RNA 与辅助因子结合时的构象动态。我们发现，快速的辅助因子结合（t1/2 ∼ 0.7 秒）会促使 RNA 发生构象变化，从而促进甲基转移。结果表明，伪三元基团上的堆叠相互作用以及 Cu (II) 离子的螯合作用对 SAM 的结合至关重要。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Biological Chemistry Biochemistry, Genetics and Molecular Biology-Biochemistry

自引率

4.20%

发文量

1233

期刊介绍： The Journal of Biological Chemistry welcomes high-quality science that seeks to elucidate the molecular and cellular basis of biological processes. Papers published in JBC can therefore fall under the umbrellas of not only biological chemistry, chemical biology, or biochemistry, but also allied disciplines such as biophysics, systems biology, RNA biology, immunology, microbiology, neurobiology, epigenetics, computational biology, ’omics, and many more. The outcome of our focus on papers that contribute novel and important mechanistic insights, rather than on a particular topic area, is that JBC is truly a melting pot for scientists across disciplines. In addition, JBC welcomes papers that describe methods that will help scientists push their biochemical inquiries forward and resources that will be of use to the research community.