与翻译80S核糖体相关的蛋白质导导通道的架构
R Beckmann1, C M Spahn, N Eswar
1Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. roland.beckmann@charite.de
Cell
|November 10, 2001
概括
研究人员可视化了酵母核糖体新生链复合体 (RNC) 与Sec61蛋白导通道 (PCC) 相互作用. 这种结构洞察力支持对转换转移的二进制模型,简化了蛋白质向内质网膜的目标.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 细胞生物学 细胞生物学
背景情况:
- 该Sec61复合体形成了蛋白质导导通道 (PCC) 在内分泌网膜膜.
- 核糖体新生链复合体 (RNCs) 开始在ER膜上进行蛋白质转位.
- 了解RNC-PCC相互作用对于破译共翻译转位至关重要.
研究的目的:
- 为了结构性地描述酵母RNC和Sec61复合体之间的相互作用.
- 阐明了对ER的协译蛋白向的分子基础.
- 提出一个功能模型,用于转位期间的核糖体通道复合体.
主要方法:
- 在体外组装酵母RNC与信号序列.
- 对RNC-Sec61复合物的免疫净化.
- 低温电子显微镜 (cryo-EM) 用于以15.4 Å分辨率进行结构重建.
主要成果:
- 一个冷EM结构揭示了RNC的P位点中的tRNA与Sec61复合体结合.
- 在狭窄的间隙中观察到四种不同的连接,分别在核糖体组件和PCC之间.
- Sec61复合物以紧的三元体的形式出现,并影响了一种动态的rRNA元素 (扩展段27).
结论:
- 该研究提供了RNC-Sec61综合体的高分辨率结构快照.
- 这些发现支持共翻译转位的简化二进制模型.
- 这种模型涉及翻译核糖体通道复合体的两个基本功能状态.
相关概念视频
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...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Membrane Proteins
Plasma membranes have integral transmembrane proteins involved in facilitated transport. These proteins are collectively referred to as transport proteins, and they function as either channels for the material or as carriers themselves. Channel proteins have hydrophilic domains exposed to the intracellular and extracellular fluids and a hydrophilic channel through their core that provides a hydrated opening for solutes to pass through the membrane layers. Passage through the channel allows...
The ADP/ATP Carrier Protein
ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational...
Oligosaccharide Assembly
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
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...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Protein Translocation Machinery on the ER Membrane
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.


