ATPase活性部位的静电相互作用控制了100kDa SecA转位酶的总体构造
Dorothy M Kim1, Haiyan Zheng, Yuanpeng J Huang
1Department of Biological Sciences and Northeast Structural Genomics Consortium, 702A Fairchild Center, MC2434, Columbia University, New York, New York 10027, USA.
Journal of the American Chemical Society
|November 22, 2012
概括
在SecA酶中的单个电荷.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 蛋白质的运输方式
背景情况:
- SecA是细菌中蛋白质分泌的关键机械酶.
- 它的ATPase电机与DEAD-boxRNA基酶具有同质性.
- 了解局部ATP水解如何影响SeCA的全球形状是关键.
研究的目的:
- 为了研究静电电荷在SeCA的ATPase活性部位中的作用.
- 阐明将局部化学事件与全球结构变化联系在一起的机制.
- 为了描述SeCA的全性机械化学,Seca.
主要方法:
- 生物物理方法,包括热量计.
- 在催化基中发生异基突变 (从谷氨酸变成谷氨胺).
- -交换质谱仪. 交换质谱仪.
主要成果:
- 在ATPase活性位点中的单个静电电荷控制SeCA的总体构造.
- 谷氨酸转化为谷氨胺的突变促进或触发了酶的结构转变.
- 这种突变增加了远程部位的蛋白质骨干动力学,表明了全调节.
结论:
- 在ATP水解过程中的局部静电变化与SeCA的全球形态和动态变化相结合.
- 这种合是由结构相互作用的复杂网络介导的.
- SecA的全性机械化学有效地将化学能量转化为用于蛋白质运输的机械工作.
相关概念视频
ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
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In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
Energy to Drive Translocation
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...


