一个遥远的表面循环调节了酸中核心结构和冷活性,而酸则调节了基基转移酶的冷活性
Yewon Nam1, Jisub Hwang1, Bogeun Kim1,2
1Division of Life Sciences, Korea Polar Research Institute, Incheon, Republic of Korea.
PloS one
|March 12, 2026
概括
在适应寒冷的细菌中,一种独特的酶插入可在低温下增强酸丁氨基基转移酶 (PPAT) 活性. 这种适应性保持了酶的灵活性和基质的吸引力,这对心理友好代谢至关重要.
科学领域:
- 生物化学和分子生物学
- 酶学 是一种酶学.
- 结构生物学 结构生物学
- 寒冷适应机制 寒冷适应机制
背景情况:
- 素丁氨基转移酶 (PPAT) 对于辅酶A生物合成和细胞代谢至关重要.
- 了解心理友好生物体中的PPAT适应对于理解寒冷环境生物化学至关重要.
- 喜欢寒冷的微生物中PPAT的特定适应机制在很大程度上是未知的.
研究的目的:
- 来自心理友好型甲类植物Methylocapsa palsarum (MpaPPAT) 的PPAT的结构和功能.
- 为了研究MpaPPAT在寒冷适应中独特的表面暴露环插入的作用.
- 阐明MpaPPAT在低温下增强活性背后的分子机制.
主要方法:
- 序列分析以确定MpaPPAT中独特的结构特征.
- 确定野生型MpaPPAT和循环删除突变体的晶体结构.
- 比较生化分析以评估不同温度下的催化活性.
主要成果:
- 在MpaPPAT中发现了一种独特的五氨基酸插入 (SCRLS),在心理友好同类中保存.
- 在10-20°C时,WT MpaPPAT表现出高活性,而突变MpaPPAT (Δ67-71) 则表现出低温活性.
- 结构分析显示,SCRLS删除导致全变化:H4螺旋硬化和改变中央孔电静态.
结论:
- 该SCRLS插入为MpaPPAT寒冷适应起到关键的全调节器作用.
- 这种插入保持了六米芯的灵活性,并确保了在低温下基板结合的正中央通道.
- 这项研究揭示了通过形状灵活性和静电转向的酶冷适应的双重机制.
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