一个过渡反应中间体的观察揭示了AAA-ATPase p97的机械化学循环
在PubMed上查看摘要
概括
此摘要是机器生成的。研究人员实时可视化了人体ATPase p97 (也称为含瓦洛蛋白). 他们确定了一个关键的中间状态, 对于调节ATP循环和酶功能至关重要, 提供了对疾病机制的洞察力.
科学领域
- 生物化学
- 分子生物学
- 结构生物学
背景情况
- 人类ATPase p97 (含瓦洛蛋白/Cdc48) 是一个重要的AAA+蛋白机器,参与细胞能量过程.
- 功能失调的p97与癌症和退行性疾病有关,强调其治疗潜力.
研究的目的
- 实时监测人类p97的酶活性.
- 阐明将ATP循环与机械工作相结合的机械化学步骤.
- 了解疾病相关突变在p97功能中的作用.
主要方法
- 使用一种基于NMR的新方法实时监测酶活性.
- 集成的溶液状态和固态NMR技术.
- 研究了蛋白质及其核酸结合状态中的构造转变.
主要成果
- 直接检测了短暂的ADP.Pi核酸状态,这是ATPases中长期寻求的中间体.
- 确定了这种中间体在p97的第一个核酸结合域内的ATP循环调节中的关键作用.
- 证明功能增益突变如何破坏p97的酶循环.
结论
- 这项研究提供了对p97在酶循环中的动态构造变化的高分辨率见解.
- 鉴定到的中间体和突变的影响为p97调节和疾病机制提供了更深入的理解.
- 使用的NMR方法广泛适用于研究其他大型分子机器.
相关概念视频
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...
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...
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, 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...
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...
ATP is a highly unstable molecule. Unless quickly used to perform work, ATP spontaneously dissociates into ADP and inorganic phosphate (Pi), and the free energy released during this process is lost as heat. The energy released by ATP hydrolysis is used to perform work inside the cell and depends on a strategy called energy coupling. Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions, allowing them to proceed.
One example of energy coupling using ATP involves a...

