由冷电子显微镜可视化的多重结合部位建议的谷氨酸脱酶上的辅酶结合途径
Taiki Wakabayashi1,2,3, Mao Oide1,2,3,4, Takayuki Kato5
1Department of Physics, Faculty of Science and Technology, Keio University, Yokohama, Japan.
The FEBS journal
|September 8, 2023
概括
低温电子显微镜揭示了尼古丁胺胺氨基二核酸 (NADP) 如何与谷氨酸脱酶 (GDH) 结合. 这些发现揭示了NADP的存在.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 谷氨酸脱酶 (GDH) 是细胞代谢中的关键酶.
- 了解辅助因子结合机制是酶功能的关键.
- GDH以六合体的形式存在,具有参与催化和辅因子结合的独特域.
研究的目的:
- 为了可视化六次性GDH与尼古丁胺胺二核酸盐 (NADP) 的结构.
- 为了研究NADP到GDH活性部位的联结通路.
- 阐明构造变化在NADP结合中的作用.
主要方法:
- 低温传递电子显微镜 (cryo-EM) 用于确定GDH-NADP复合物的结构.
- 使用聚焦分类来解决核酸结合域的结构异质性.
- 测量了酶动力学,以评估观察到的结合模式的功能相关性.
主要成果:
- 确定了与NADP复合的GDH六合体的2.4 Å分辨率的冷EM结构.
- 在活性位点裂内确定了五个不同的NADP结合位点.
- 三个结合点表明NADP进入的主要途径,而另外两个在催化过程中似乎不那么常见.
结论:
- 这项研究提供了对NADP与GDH的动态结合的结构性见解.
- 联体诱导的构造变化促进NADP进入活性部位.
- 这些发现有助于理解GDH活动的调节.
相关概念视频
Cryo-electron Microscopy
3.4K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
3.4K
ATP Synthase: Structure
12.6K
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...
12.6K
Amino Acid Biosynthetic Pathways
35
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which...
35
Electron Transport Chain: Complex III and IV
7.6K
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...
7.6K
ATP Synthase: Mechanism
14.7K
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...
14.7K
Electron Transport Chains
99.3K
The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...
The ETC is comprised of...
99.3K


