揭开Staphylococcus aureus lysyl-tRNA合成酶对基质识别的可塑性及其对失速化的影响
Jaykumar Jani1, Jigneshkumar Mochi1,2, Smit Shah1
1School of Life Sciences, Central University of Gujarat, Gandhinagar, India.
The FEBS journal
|July 7, 2025
概括
黄金葡萄球菌lysyl-tRNA合成酶与不正确的氨基酸误导转移RNA (tRNA),影响蛋白质合成和细胞生长. 结构和突变研究确定了导致这种错位化错误的关键残留物.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 转移RNA (tRNA) 错误结合,tRNA与非同源氨基酸的充电,损害了转化忠实度.
- 这一过程可能导致错误的氨基酸被纳入蛋白质中,这可能会影响细胞功能.
- 了解错化机制对于理解细胞调节和疾病状态至关重要.
研究的目的:
- 为了阐明tRNALys被Staphylococcus aureus lysyl-tRNA合成酶 (SaLysRS) 误导的结构和分子基础.
- 为了研究SaLysRS介导的错化对蛋白质合成和细胞活性的功能后果,在体内.
- 在SaLysRS中识别特定的氨基酸残留物,对于同源和非同源基质的识别至关重要.
主要方法:
- 酶活性检测量量化失糖率.
- 在体内研究和MALDI-TOF质谱检测错误充电的tRNA和内置的氨基酸.
- 进行X射线晶体学以确定SaLys.RS.的三维结构.
- 针对位点的突变发生和分子动力学模拟,以分析残留物的功能.
主要成果:
- 发现SaLysRS与甲氨酸和氨酸对tRNALys产生不当结合.
- 错误充电的tRNA被用于蛋白质翻译,导致非同类甲和氨酸被纳入蛋白质中.
- 结构分析揭示了关键的残留物和保留基因参与基质结合,Glu233,Tyr273和Glu420被确定为正确和不正确的氨基酸结合的关键.
- 氨基酸的错误结合对细菌细胞生长产生了负面影响.
结论:
- 这项研究提供了对SaLysRS的错化机制的结构和生化见解,突出了涉及基质选择的特定残留物.
- 这些发现表明,SaLysRS介导的错基化直接影响转化忠实性和细胞适应性.
- 这项研究增强了对tRNA合成酶特异性的理解,以及氨基化过程中错误的后果.
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