双重DNA和RNA特异性的结构基础是G-四重复溶解的DEAH盒酶DHX36
Michael T Banco1, Tapas Paul2, Jiansen Jiang1
1Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Cell reports
|August 20, 2025
概括
DEAH盒子酶36 (DHX36) 可以分解DNA和RNA的G四重复. 结构和运动研究揭示了特定的域和循环如何使DHX36能够区分DNA和RNA基质.
科学领域:
- 分子生物学
- 结构生物学
- 生物化学
背景情况:
- 对于真核生物的基因表达来说,DEAH盒酶至关重要.
- DHX36 (DEAH-box helicase 36) 具有独特的解脱DNA和RNAG四重复的能力.
- 了解DHX36的基质多功能性是解读其生物作用的关键.
研究的目的:
- 阐明DHX36的双重DNA/RNA G四重复分辨率的分子机制.
- 为了确定DHX36的基质歧视的结构基础.
- 研究特定蛋白质域和循环在G-四重复识别中的作用.
主要方法:
- 电子显微镜 (cryo-EM) 用于确定DHX36与RNA和DNAG四重复的高分辨率结构.
- 用于测量酶活性的动力测试.
- 单分子弗斯特共振能量转移 (smFRET) 用于研究形态动力学.
- 结构引导的突变发生以检测蛋白质的功能.
主要成果:
- 冷-EM结构显示DHX36与三层RNA和六层DNAG四重复合体结合.
- 螺旋酶核的RecA2域在区分DNA和RNA基质方面发挥着至关重要的作用.
- 一个分离的RecA2表面循环和一个N终端延伸一起工作,以特别识别G-四重复结构.
结论:
- DHX36的多功能性源于其保存的核心和专门的外围元件之间的协同作用.
- RecA2域及其相关循环是DNA与RNA特异性的关键决定因素.
- 对DEAH盒子酶基体的识别的一般原则可能涉及核心装饰和外围元素相互作用.
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