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研究揭示植物Dicer酶识别切割RNA的机制
作者:小柯机器人 发布时间:2021/10/17 20:01:20

南方科技大学杜嘉木等研究人员合作揭示植物Dicer酶识别切割RNA的机制。该研究于2021年10月14日在线发表于国际一流学术期刊《科学》。

研究人员表示,在真核生物中,小RNA(sRNA)在多个生物过程中发挥着关键作用。Dicer核酸内切酶是sRNA生物生成的核心。在植物中,DICER-LIKE PROTEIN 3 (DCL3)产生24nt的小干扰RNA(siRNA),决定了RNA引导的DNA甲基化(RdDM)途径的特殊性。

研究人员确定了DCL3-pre-siRNA复合物在活性切割能力状态下的结构。向导链的5′-磷酸化A1和互补链的1-nt 3′-悬链分别被一个带正电的口袋和一个芳香帽特异性地识别。24-nt siRNA长度依赖的是引导RNA的5′-磷酸化端与成对的RNaseIII结构域形成的双切割位点之间的分离。这些结构研究并结合功能数据,揭示了对一般Dicer切割原理的见解。

附:英文原文

Title: Mechanism of siRNA production by a plant Dicer-RNA complex in dicing-competent conformation

Author: Qian Wang, Yan Xue, Laixing Zhang, Zhenhui Zhong, Suhua Feng, Changshi Wang, Lifan Xiao, Zhenlin Yang, C. Jake Harris, Zhe Wu, Jixian Zhai, Maojun Yang, Sisi Li, Steven E. Jacobsen, Jiamu Du

Issue&Volume: 2021-10-14

Abstract: In eukaryotes, small RNAs (sRNAs) play critical roles in multiple biological processes. Dicer endonucleases are central to sRNA biogenesis. In plants, DICER-LIKE PROTEIN 3 (DCL3) produces 24-nt small interfering RNAs (siRNAs) that determine the specificity of the RNA-directed DNA methylation (RdDM) pathway. Here, we determined structure of a DCL3-pre-siRNA complex in an active dicing-competent state. The 5′-phosphorylated-A1 of the guide strand and the 1-nt 3′-overhang of the complementary strand are specifically recognized by a positively charged pocket and an aromatic cap, respectively. The 24-nt siRNA length dependence relies on the separation between the 5′-phosphorylated-end of the guide RNA and dual cleavage sites formed by the paired RNaseIII domains. These structural studies, complemented by functional data, reveal insights into the dicing principle for Dicers in general.

DOI: abl4546

Source: https://www.science.org/doi/10.1126/science.abl4546

 

期刊信息
Science:《科学》,创刊于1880年。隶属于美国科学促进会,最新IF:41.037