相关实验视频

Updated: Jan 18, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

Published on: May 13, 2020

来自Mycobacterium tuberculosis的MmpS4-MmpL4复合体的结构阐明

Jennifer C Earp, Nicolas P Lichti, Alisa A Garaeva

bioRxiv : the preprint server for biology

|January 16, 2026

概括

研究人员可视化了Mycobacterium结核病MmpL4输送器复合体,揭示了其卷轴-卷轴域和对出口mycobactin和bedaquiline至关重要的形状变化.

科学领域:

结构生物学是结构生物学.
微生物学微生物学
生物化学生物化学

背景情况:

结核菌菌具有十三个MmpL转运器,参与出口各种分子.
MmpL4和MmpL5,以及MmpS4和MmpS5,负责出口 siderophore mycobactin 和 bedaquiline 药物.
以前的研究确定了MmpL4单体结构,缺少一个关键的线圈-线圈域.

研究的目的:

为了确定六美体 (MmpS4) 3-(MmpL4) 3复合体的冷-EM结构.
为了描述MmpL4在六米复合体中的构造.
建立可变蛋白质复合体的冷EM研究工作流程.

主要方法:

由AlphaFold预测指导的合理二硫化物交叉链接.
单粒子冷电子显微镜 (冷电子显微镜).
测定MmpS4-MmpL4复合体的结构.

主要成果:

(MmpS4) 3-(MmpL4) 3复合体的冷-EM结构揭示了MmpL4.4的卷轴-卷轴域.
卷轴-卷轴域以~60°的角度突出进入周围质.
与单体相比,MmpL4在六合体中表现出明显的形状,具有周等离子腔和重新排列的质子合残留物.

结论:

这项研究为MmpL4-MmpS4复合体提供了第一个结构洞察.
这些发现阐明了mycobactin和bedaquiline出口的结构基础.
开发的工作流允许对具有挑战性的,不稳定的蛋白质复合体进行结构研究.

更多相关视频

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin

Published on: March 10, 2021

Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies

Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies

Published on: November 28, 2017

相关概念视频

Protein Complex Assembly

Protein Complex Assembly

Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...

Microtubule Associated Proteins (MAPs)

Microtubule Associated Proteins (MAPs)

Microtubule function and architecture are regulated by an array of specialized proteins called microtubule-associated proteins or MAPs. These proteins are widespread across different organisms and have conserved protein motifs, like the multi-TOG domain for tubulin binding found in the CLASP family of MAPs. Some MAPs are lineage-specific based on their conserved domains. Their functions depend upon the cytoskeletal architecture and cell type they are located within. In-plant cells, a specific...