相关实验视频
Updated: Jun 26, 2026

08:49
Peering at Brain Polysomes with Atomic Force Microscopy
Published on: March 16, 2016
细菌多体的本地3D组织
Florian Brandt1, Stephanie A Etchells, Julio O Ortiz
1Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried 82152, Germany.
Cell
|January 27, 2009
概括
研究人员使用冷电子断层扫描在多体体中绘制了细菌核糖体的3D组织图. 核糖体沿着mRNA形成分层排列,优化新生的多链折叠并防止聚合.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物物理学的生物物理.
背景情况:
- 最近的进展已经阐明了细菌核糖体结构.
- 在多元体内,核糖体的3D组织仍然不太清楚.
研究的目的:
- 为了研究细菌70S核糖体在多核糖体中的三维排列.
- 了解核糖体组织如何影响新生的多链折叠.
主要方法:
- 低温电子断层扫描用于在玻璃化细菌转化提取物和大肠杆菌溶解物中可视化核糖体.
- 采用模板匹配方法来绘制70S核糖体的位置和方向.
主要成果:
- 多体体表现出密集包装的核糖体,具有首选的方向.
- 沿着mRNA观察到核糖体的分层或伪螺旋组织.
- mRNA在内部被隔离,可访问的tRNA入口和聚的出口点面向细胞质.
结论:
- 这种安排最大限度地提高了新生链之间的距离,减少了聚合.
- 观察到的多体结构有助于新合成的蛋白质的生产折叠.
相关概念视频
Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Coordination of Gene Expression Processes in Bacteria
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
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...
Prokaryotic Gene Structure and Organization
Prokaryotic genomes exhibit a streamlined organization of coding and non-coding regions essential for gene expression and protein synthesis. While coding regions contain the genetic instructions for proteins or functional RNAs, non-coding regions regulate the precise transcription and translation of these genes.Coding Regions: Proteins and RNAsThe primary coding regions, known as structural genes, include sequences transcribed into messenger RNA (mRNA) and ultimately translated into...
Nucleoid
The nucleoid represents a structurally and functionally distinct region within prokaryotic cells, where the cell's DNA and associated proteins are housed. Unlike eukaryotic cells, prokaryotes lack a membrane-bound nucleus, and the nucleoid facilitates the organization and accessibility of the genetic material within this constraint. The DNA in most bacteria and archaea exists as a single, circular, double-stranded molecule that is highly compacted through supercoiling and interactions with...

