圆形家族内膜蛋白酶的晶体结构
Yongcheng Wang1, Yingjiu Zhang, Ya Ha
1Department of Pharmacology, Yale School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA.
Nature
|October 20, 2006
概括
大肠杆菌 GlpG 的晶体结构揭示了其在膜内的活性部位,这表明膜内蛋白解发生在水环境中. 一个封闭机制可能控制了基质进入酶的途径.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 膜生物学 膜生物学
背景情况:
- 大肠杆菌 GlpG 是rhomboid蛋白酶家族中的一个组成膜蛋白.
- 状蛋白酶可以切割膜蛋白的跨膜域,类似于Site-2蛋白酶 (S2P) 和马分泌酶.
研究的目的:
- 为了确定 GlpG 核心域的高分辨率晶体结构.
- 通过 GlpG 阐明膜内蛋白解的结构基础.
主要方法:
- 采用X射线晶体学,获得了GlpG核心域的2.1A分辨率的晶体结构.
- 对蛋白质结构的分析确定了关键的残留物,水分子和基质接入通路.
主要成果:
- GlpG结构揭示了六个带有催化Ser-His二的跨膜段,位于蛋白质内部,在膜表面以下.
- 一个V形的开口为基板提供了侧面的接入,但被一个循环部分阻塞了,这表明一个关门机制.
- 活性部位位于疏水膜双层内,表明键分裂发生在这种环境中.
结论:
- GlpG的内膜蛋白解发生在疏水膜双层内.
- 一种新的封闭机制可能会调节基质进入GlpG.活性部位的途径.
- 这些结构性见解有助于我们更好地了解状蛋白酶功能和膜内蛋白解.
相关概念视频
Protein Folding
Overview
Structural Protein Function
Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
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Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Insertion of Multi-pass Transmembrane Proteins in the RER
The rough ER membrane synthesizes, assembles, and embeds transmembrane proteins in diverse topologies. These proteins function as transporters or channels and can remain in the ER membrane or are sent to the Golgi complex, lysosome, and cell membrane.
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
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Structural Protein Function
Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
The Proteasome Structure
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...


