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考古DIMT1的结构和功能表征揭示了有效催化所必需的独特蛋白质动力学

Sayan Saha¹, Shankar Prasad Kanaujia¹

¹Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.

Structure (London, England : 1993)

|August 15, 2024

概括

古老的二甲基氨酸转移酶1 (DIMT1) 在核糖体生物发生过程中经历独特的域移动. 像S-adenosyl-L-methionine (SAM) 这样的辅因子结合对其功能至关重要,而抑制剂则阻断了活性.

科学领域:

结构生物学结构生物学
分子生物学分子生物学
生物化学生物化学

背景情况:

甲基氨酸转移酶1 (DIMT1),是一种细菌KsgA的正经体,对细菌和真核生物中的核糖体生物发生至关重要.
考古物DIMT1及其动态机制在很大程度上仍未被描述.
了解DIMT1的动态对于阐明核糖体组装途径至关重要.

研究的目的:

从结构和功能上描述Pyrococcus horikoshii的考古DIMT1在apo和holo状态.
研究共因子和抑制剂在DIMT1动态和活性中的作用.
阐明在考古 DIMT1.1.中的基质结合和催化机制.

主要方法:

使用X射线晶体学来确定Pyrococcus horikoshii DIMT1.1.的apo和Holo形式的结构.
对野生类型蛋白质和突变物进行分析,以捕捉不同的过渡状态 (开放,闭合,中间).
生物化学试验评估辅助因子 (SAM,SAH) 和抑制剂 (sinefungine) 对酶活性的影响.

主要成果:

在考古DIMT1.1中发现了一种对基质 (RNA) 定位至关重要的独特的域间运动.
这种运动取决于相关的辅因子S-adenosyl-L-methionine (SAM) 或S-adenosyl-L-homocysteine (SAH) 的存在.
抑制剂 sinefungine 与催化口袋结合,阻断基质的接入,使酶变得不活跃.

结论:

阿基亚DIMT1表现出对其在核糖体生物发生中的催化功能至关重要的辅因子依赖的构造变化.
这项研究为考古DIMT1.1.的结构动态和催化机制提供了新的见解.
这些发现有助于更深入地了解生命的不同领域的核糖体组装.

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