相关实验视频

Updated: Jun 27, 2025

High-resolution Single Particle Analysis from Electron Cryo-microscopy Images Using SPHIRE

High-resolution Single Particle Analysis from Electron Cryo-microscopy Images Using SPHIRE

Published on: May 16, 2017

通过单颗粒冷EMEM揭示的细菌氨基氨酸合成酶结构

Vitor Hugo Balasco Serrão^1,2, Karine Minari³, Humberto D'Muniz Pereira⁴

¹Biomolecular Cryoelectron Microscopy Facility, University of California - Santa Cruz, Santa Cruz, CA, 95064, United States.

Current research in structural biology

|April 29, 2024

概括

细菌单氨酸合成酶 (SelA) 的结构使用冷EM确定. 这揭示了它的十倍结构和活性部位,对于合成第21个氨基酸 - - 单半氨酸至关重要.

科学领域:

生物化学生物化学
结构生物学结构生物学
微生物学微生物学

背景情况:

单半氨酸 (Sec) 是第21个氨基酸,在专门的转移RNA (tRNA^Sec) 上合成.
在细菌中,单半氨酸合成酶 (SelA) 催化了来自Ser-tRNA^[Ser]Sec的Sec生物合成.
了解SelaA结构是其催化机制和通路调节的关键.

研究的目的:

为了确定细菌SelaA.的综合冷电子显微镜 (cryo-EM) 结构.
阐明 SelA 在氨基氨酸生物合成中的功能和调节的结构基础.
为了比较细菌SelA结构与古生物/真核生物对应物.

主要方法:

净化复合的 *大肠杆菌 * SelA.
单粒子冷电子显微镜 (SPA cryoEM) 用于结构确定.
高分辨率结构分析 (2.69 Å分辨率).

主要成果:

细菌SelaA的冷-EM结构在2.69 Å分辨率下得到解析.
塞拉采用了十米的结构,具体来说是二米的五米结构.
确定并描述了活性部位,基质结合口袋和催化残留物K295.
在细菌和古生物/真核细胞SelaA之间注意到了结构上的差异.

结论:

脱化对于细菌SelaA的功能至关重要.
该结构为SelaA的催化机制提供了详细的见解.
结构变异支持细菌与古生物/真核生物的Sec生物合成途径的独立进化.

关键词:

这就是SelaAA的意义.单半氨酸是一种单半氨酸.单半氨酸合成酶的作用是什么一个粒子分析分析.的tRNA[Ser]Sec 的时间.

更多相关视频

Single Particle Cryo-Electron Microscopy: From Sample to Structure

Single Particle Cryo-Electron Microscopy: From Sample to Structure

Published on: May 29, 2021

Combining X-Ray Crystallography with Small Angle X-Ray Scattering to Model Unstructured Regions of Nsa1 from S. Cerevisiae

Combining X-Ray Crystallography with Small Angle X-Ray Scattering to Model Unstructured Regions of Nsa1 from S. Cerevisiae

Published on: January 10, 2018

相关概念视频

Cryo-electron Microscopy

Cryo-electron Microscopy

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...

Studying the Cytoskeleton

Studying the Cytoskeleton

The cytoskeletal architecture can be studied using different microscopic and biochemical techniques. Electron microscopy was instrumental in discovering the cytoskeletal architecture around the 1960s, which allowed obtaining structural information at a high-resolution level. However, the sample preparation procedure often limits this ability in biological samples. Several protocols have been developed over the years to optimize sample preparation. In one of the protocols known as rotary...