在二维HypA中和部位之间的通信:金属识别和pH传感
Robert W Herbst1, Iva Perovic, Vlad Martin-Diaconescu
1Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Journal of the American Chemical Society
|July 29, 2010
概括
金属沙佩龙HypA调节了Helicobacter pylori中的流量,根据pH和水平调整其位结构,以确保尿酶和酶酶的成熟.
科学领域:
- 生物化学 生物化学
- 微生物学 微生物学
- 结构生物学 结构生物学
背景情况:
- 杆菌需要依赖的金属酶才能在胃的低pH环境中生存.
- 金属沙佩龙HypA对于这些含的酶,尿酶和NiFe-酶的成熟至关重要.
- HypA 具有明显的和结合点,这对其功能至关重要.
研究的目的:
- 为了研究HypA部位的结构动态,以响应pH和结合.
- 阐明HypA感知并响应细胞的可用性和pH的机制.
- 了解HypA的金属位点在控制运输中对酶成熟的作用.
主要方法:
- 在不同的pH条件下使用X射线吸收光谱 (XAS) 分析位结构.
- 核磁共振光谱学用于研究 (((II) 结合后的HypA形状变化.
- 位点定向的突变发生,以探测金属结合和pH传感中的关键残留物的功能.
- 实验室尿酶活性测试用于评估HypA突变的功能影响.
主要成果:
- 在HypA部位表现出结构性可塑性,在pH值6.3.3时从Zn (Cys) 转变为Zn (His) 转变为Zn (Cys) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (Cys) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (Cys) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (His) 转变为Zn (Cys) 转变为Zn (His) 转变为Zn (His) 转变为Zn (Cys) 转变为Zn (His)
- 结合会诱导HypA的形状变化,包括潜在的二元形成和改变的形状.
- 在低pH下,结合固态度下降,而结合基因的突变取消了pH和的响应性.
结论:
- HypA充当传感器,动态调整其位结构,以调节传递至关重要的金属酶.
- 观察到的结构和结合变化突出显示了一种复杂的机制,用于控制H. pylori内的平衡.
- HypA感知pH和的能力对于细菌在胃环境中的生存和毒性至关重要.
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