一个5kDa域的二元化定义了5MDa的细菌性酸盐脱酶复合体的结构
Sarah Meinhold1, Rafal Zdanowicz1, Christoph Giese1
1ETH Zürich, Institute of Molecular Biology and Biophysics, Otto-Stern-Weg 5, 8093 Zürich, Switzerland.
Science advances
|February 7, 2024
概括
大肠杆菌的酸盐脱酶复合体 (PDHc) 结构揭示了一种新的机制,即外围亚单元结合域 (PSBDs) 减小. 这种PSBD二分化决定了PDHc大复合体的组装和石化学.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 大肠杆菌的酸盐脱酶复合体 (PDHc) 是一个大型的多酶组件,对细胞代谢至关重要.
- PDHc包括催化子单元:pyruvate脱酶 (E1),二利胺酸乙烯转移酶 (E2) 和二利胺酸脱酶 (E3).
- E2核心形成一个立方体结构,外围子单元E1和E3与E2外围子单元结合域 (PSBD) 结合.
研究的目的:
- 为了阐明Escherichia coli PDHc.中子单元组合的精确机制.
- 在PDHc架构中确定外围子单元绑定域 (PSBD) 的作用.
- 确定管理PDHc大型综合体石化学的建筑决定因素.
主要方法:
- 利用一个装配停止的E2同位体 (E2_3) 来研究PSBD相互作用.
- 研究了E1二元体与PSBD二元体的合作结合.
- 确定了E3二次体在E2上的结合部位偏好.
主要成果:
- 证明了E2_3三元体内的三种PSBD中的两种是二元化的.
- 显示每个PSBD二元体合作地结合两个E1二元体.
- 揭示了E3二极体仅与E2_3结构中的未配对PSBD结合.
- 在野生类型的PDHc中确认了16个E1二元体:24个E2单元体:8个E3二元体的固体测量.
- 识别了保存的PSBD二度接口作为关键的架构决定因素.
结论:
- PSBD二分化是以前未被识别的,在马蛋白细菌PDHc大复合体的架构中的关键决定因素.
- 这种二度化机制控制了与E2核心结合的E1和E3子单元的精确静态度.
- 这些发现为这种必不可少的代谢酶综合体的结构组织和调节提供了新的见解.
相关概念视频
Pyruvate Oxidation
159.0K
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
159.0K
Electron Transport Chain: Complex I and II
13.4K
The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
ROS generation is regulated and maintained at moderate levels necessary...
13.4K
Electron Transport Chain: Complex III and IV
7.5K
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
7.5K
Conservation of Protein Domains Over Different Proteins
10.9K
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
10.9K
ATP Synthase: Structure
12.4K
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...
12.4K
The Supercomplexes in the Crista Membrane
2.5K
The mitochondrial cristae membrane is the primary site for the oxidative phosphorylation (OXPHOS) process of energy conversion mediated through respiratory complexes I to V. These complexes have been widely studied for decades, and it has been proven that they form supramolecular structures called respiratory supercomplexes (SC). These higher-order complexes may be crucial in maintaining the biochemical structure and improving the physiological activity of the individual complexes while...
2.5K


