基于不对称的晶体结构的Enterococcus hirae V1-ATPase的旋转机制
Satoshi Arai1, Shinya Saijo, Kano Suzuki
1Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.
Nature
|January 22, 2013
概括
空腔ATPases (V-ATPases) 是重要的质子和癌症和骨质疏松症的药物标. 这项研究揭示了V(1)-ATPase的高分辨率不对称结构,阐明了其旋转电机机制.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物物理学 分子生物物理学
背景情况:
- 空腔ATPases (V-ATPases) 是细胞膜中必不可少的质子,涉及骨再吸收和癌症转移.
- 该V(1) 部分充当旋转电机,但由于有限的高分辨率结构数据,其精确的分子机制尚不清楚.
- 之前的工作建立了Enterococcus hirae V(1)-ATPase的体外表达,净化和复制.
研究的目的:
- 确定无核酸和核酸结合的V(1) -ATPase A(3) B(3) 复合体的高分辨率不对称结构.
- 为了阐明V(1) -ATPase旋转电机的分子机制.
- 提供关于V-ATPases中核酸结合和ATP水解的见解.
主要方法:
- 使用X射线晶体学 (2.8 Å和3.4 Å分辨率) 确定无核酸和核酸结合的V(1) -ATPase A(3) B(3) 复合物的不对称结构.
- 无核酸和核酸结合的晶体结构确定V(1)-ATPase (2.2 Å和2.7 Å分辨率).
主要成果:
- 报告了无核酸 (2.8 Å) 和核酸结合 (3.4 Å) V(1) -ATPase A(3) B(3) 复合物的不对称结构.
- 通过核酸结合引起的观察到的构造变化,表明一个合作的,右手旋转结合顺序.
- 确定无核酸 (2.2 Å) 和核酸结合 (2.7 Å) V(1)-ATPase 的结晶结构.
- 在DF复杂结合时确定了一个更紧密的核酸结合点.
- 表明ATP水解是由保存的氨酸残留物的接近刺激的.
结论:
- 这项研究提供了V(1) -ATPase旋转机制的第一个高分辨率图像.
- 这些发现阐明了V-ATPase功能所必需的结构变化和合作性核酸结合.
- 这些结构为理解V-ATPase活性和开发向治疗提供了分子基础.
相关概念视频
01:48ATP 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...
01:18ATP 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...
01:30ATP 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...
01:34ATP 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...
01:27ATP 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...
01:43The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...