一个古老的核酸结合的意想不到的酶功能
Rylan R Watkins1, Stella Bockelman1, Anna Vradi1
1Department of Chemistry and Biochemistry, Center for RNA Biology, Ohio State University, Columbus, OH, 43220, United States.
Nucleic acids research
|April 24, 2025
概括
虫菌MCP1,一种具有OB折叠的蛋白质,意外地去糖化了Ala-tRNAs,确保了翻译的真实性. 这种保存函数突出显示了一个古老的核酸结合域.
科学领域:
- 分子生物学分子生物学
- 生物化学 生化学
- 遗传学 是一个遗传学.
背景情况:
- 氨基酸-tRNA合成酶 (ARS) 对于蛋白质合成的忠实性至关重要.
- 细胞ARS组装成一个多氨基酸-tRNA合成酶复合体 (MSC).
- 虫菌MSC含有OB折叠蛋白MCP1和MCP2,以及脱酶MCP3.
研究的目的:
- 调查MCP1.1尚未探索的酶活性.
- 确定MCP1在Trypanosoma bruceiMSC中的作用.
- 了解OB折叠蛋白在tRNA代谢中的功能意义.
主要方法:
- 复合表达和MCP1.1的净化.
- 使用Ala-tRNAs进行了体外脱氧化试验.
- 域删除和MCP1.1的局部定向突变发生.
- 使用Saccharomyces cerevisiae Arc1p.进行跨物种互补测定.
主要成果:
- 再组合的MCP1表现出Ala-tRNA脱氧化活性.
- MCP1的OB-fold包含了用于脱的催化口袋.
- 在OB-fold中的关键残留物 (K326,R331,S335) 对于活动至关重要.
- 在Saccharomyces cerevisiae中保留了MCP1的脱功能.
结论:
- MCP1具有一种新的,保存的tRNA脱氧化活性.
- OB-fold域在核酸代谢中具有意想不到的酶功能.
- 这一发现解释了这种蛋白质家族的3' CCA-end结合活性.
- 这项研究揭示了OB-fold域在保持翻译准确性方面的古老功能.
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