相关实验视频

Updated: Jul 6, 2025

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking

Published on: December 17, 2013

在 Bacteroidota 的第六类分泌系统中组装一个独特的膜复合体

Thibault R Bongiovanni^1,2, Casey J Latario³, Youn Le Cras⁴

¹Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 7255, Institut national de la santé et de la recherche médicale (INSERM), Marseille, France.

Nature communications

|January 10, 2024

概括

研究人员在Bacteroidota细菌中发现了一种新型的膜复合体 (MC),该复合体对于VI型分泌系统 (T6SS) 至关重要. 这一发现揭示了独特的细菌分泌机制及其进化适应.

科学领域:

微生物学微生物学
细菌细胞生物学细菌细胞生物学
蛋白质生物化学蛋白质生物化学

背景情况:

六型分泌系统 (T6SS) 是格拉姆阴性细菌中关键的毒性因子,通过效应蛋白传递使细菌之间的竞争成为可能.
在蛋白质细菌中,T6SS被一个大型膜复合体 (MC) 定,但同源基因在Bacteroidota T6SS基因组中不存在.
这种缺失表明T6SS架构在主要细菌类之间存在差异.

研究的目的:

为了识别和描述Bacteroidota.中T6SS膜复合物的组成部分.
阐明这个新型MC的结构,组装和功能.
了解巴克特罗伊多塔和蛋白质细菌T6SS MCs之间的进化关系.

主要方法:

在Bacteroides fragilis中识别重要的T6SS基因 (tssNQOPR).
净化了TssNQOPR综合体的污染.
电子显微镜用于结构分析和复杂维度的确定.
蛋白质与蛋白质相互作用研究,以绘制组装网络的地图和石化计.

主要成果:

在B. fragilis中,五个对T6SS功能至关重要的基因 (tssNQOPR) 编码了一个新型的,针对Bacteroidota的MC.
该MC被净化,并通过电子显微镜确定其尺寸.
一个蛋白质-蛋白质相互作用网络揭示了TssNQOPR组件的组装路径和石化学,TssN将MC与基板相连接.

结论:

细菌杆菌对其T6SS具有独特的,非同类的MC,与蛋白质细菌系统不同.
已识别的TssNQOPR蛋白质构成了这一新型MC,对于T6SS的定和功能至关重要.
尽管基因含量存在差异,但仅在T6SS位点内存在MCs,这表明T6SS anchoring机制在细菌族群中的演变趋同.

更多相关视频

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Published on: January 4, 2017

A Visual Assay to Monitor T6SS-mediated Bacterial Competition

A Visual Assay to Monitor T6SS-mediated Bacterial Competition

Published on: March 20, 2013

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...

Structure of Porins

Structure of Porins

Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...

Multi-pass Transmembrane Proteins and β-barrels

Multi-pass Transmembrane Proteins and β-barrels

In multi-pass transmembrane proteins, the polypeptide chain crosses the membrane more than once. The transmembrane polypeptide chain either forms an α-helix or β-strand structure. α-Helix containing multi-pass transmembrane proteins are ubiquitous, whereas β-strand containing ones are mainly found in gram-negative bacteria, mitochondria, and chloroplasts.
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as...

Cytoskeletal Proteins in Bacteria

Cytoskeletal Proteins in Bacteria

Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...

Mechanisms of Membrane Domain Formation

Mechanisms of Membrane Domain Formation

Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...

Clathrin Coated Vesicles

Clathrin Coated Vesicles

Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...