的晶体结构与一个绑定的ATP模拟
Chikashi Toyoshima1, Tatsuaki Mizutani
1Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan. ct@iam.u-tokyo.ac.jp
Nature
|July 2, 2004
概括
这项研究揭示了骨肌肉中的 (Ca2+) 的晶体结构,详细说明了ATP结合如何导致域重组. 这种机制解释了Ca2+离子是如何被封闭并准备释放到sarcoplasmic网膜中的.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生理学分子生理学
背景情况:
- P型ATPases是必不可少的ATP驱动的离子,通过细胞膜保持离子梯度.
- 骨肌肉中的Ca2+是P型ATPase超级家族的关键代表.
研究的目的:
- 为了阐明Ca2+封闭和运输的结构机制,由sarcoplasmic网膜Ca2+.
- 描述由ATP结合和离子相互作用引起的构造变化.
主要方法:
- 使用X射线晶体学来确定Ca2+的结构.
- 该结构在存在ATP模拟物,Mg2+和Ca2+离子的情况下得到解决.
主要成果:
- 该ATP模拟桥梁N和P细胞质域,重组的结构.
- ATP模拟物和Mg2+的结合改变了P域结构,导致A域倾斜.
- 这种形状变化导致Ca2+离子在跨膜域内封闭.
结论:
- 确定的结构提供了对运输前Ca2+离子封闭机制的洞察.
- 这项研究阐明了P型ATPase离子运输循环中的关键步骤.
- 这些发现有助于理解离子在细胞生理学中的功能.
相关概念视频
Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
ATP Driven Pumps I: An Overview
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
ATP Driven Pumps III: V-type Pumps
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...


