在模板独立DNA合成过程中,在人类TdT的活性部位中核三酸盐的协调
Svetlana I Senchurova1, Timofey E Tyugashev1, Nikita A Kuznetsov2,3
1Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Biochemistry. Biokhimiia
|February 17, 2026
概括
人类终端脱核样转移酶 (TdT) 对于免疫系统的多样性至关重要. 关键残留物 (R336,H342,D345) 的突变会破坏其功能,影响DNA合成和酶稳定性.
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:
- 人类终端脱核样转移酶 (TdT) 是DNA聚合酶,对V(D) J重组至关重要,产生免疫系统多样性.
- TdT通过独立于模板的添加核酸到DNA链来发挥作用.
- 活性部位的特定氨基酸残留物,包括R336,H342和D345,对于TdT的催化活性至关重要.
研究的目的:
- 研究关键TdT活性位点残留物 (R336,H342,D345) 中突变的功能后果.
- 阐明这些残留物在dNTP结合,原料稳定和催化效率中的作用.
主要方法:
- 分子动力学模拟来分析残留物替代的影响.
- 对突变TdT酶活性进行实验测试.
- 局部定向的突变发生产生R336Q,H342A和D345E变体.
主要成果:
- H342A突变增加了酶基质解离,并降低了dNTP的添加效率.
- D345E的替代损害了金属离子协调和催化效率.
- R336Q突变导致蛋白质不稳定,并完全丧失催化活性.
结论:
- 其余物R336,H342和D345对于TdT的结构完整性和酶功能至关重要.
- 这些残留物中的突变显著影响TdT在V(D) J重组和免疫多样性中的作用.
- 了解这些相互作用为DNA聚合酶机制提供了见解.
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