クラトリンの自己組み立ては,並行して繰り返される超ヘリックスによって媒介されます
J A Ybe1, F M Brodsky, K Hofmann
1The G. W. Hooper Foundation, Department of Microbiology and Immunology, University of California San Francisco, 94143, USA.
Nature
|June 9, 1999
まとめ
クラトリンのタンパク質構造は原子解像度で決定された. これは,クラトリンの自己組織化,軽鎖結合,および膀形成中のトリメリゼーションに不可欠な繰り返しのモチーフを明らかにしています.
科学分野:
- 細胞生物学 細胞生物学
- 構造生物学 構造生物学とは
- バイオケミストリー バイオケミストリー
背景:
- クラトリンは膜の格子にポリメリゼスし,エンドサイトーシスとオルガネルの生体生成のための膀を形成します.
- クラトリンの組成は,ライトチェーンとアダプター分子によって調節され,タンパク質の分類に影響を与えます.
- クラスリントリスケリオン (clathrin triskelion) は重鎖のトリマーで,各鎖はハブ領域の軽鎖と関連している.
研究 の 目的:
- クラトリンハブドメインの原子構造を決定する.
- クラトリンの重鎖ポリメリゼーションと軽鎖アソシエーションの構造的基礎を解明する.
- クラトリンの組立とトリメリゼーションの基礎となる分子機構を理解する.
主な方法:
- X線結晶学を用いて,クラトリンハブ断片 (残留量1,210~1,516) の原子構造を2.6 Åの解像度で決定した.
- 構造分析は,繰り返しモチーフを特定するために,決定された構造の整列を伴う.
- コンピューティング・モデリングは,クラスリンアセンブリの3次元フレームワークを提供した.
主要な成果:
- クラトリンのハブ断片の原子構造は,アルファヘリクスの長方形のコイルを明らかにした.
- クラトリンの足で7回繰り返される145の残留モチーフが特定されました.
- このモチーフは,真空タンパク質分類に関与するタンパク質にも見られます.
結論:
- 決定された構造は,クラトリンの重鎖自己組み立てのための詳細な枠組みを提供します.
- 発見は,軽鎖結合とトリメリゼーションの構造的基礎を明確にします.
- クラトリンの構造を理解することは,膜の密輸とタンパク質の分類におけるその役割を解読する鍵です.
関連する概念動画
02:50Spindle Assembly
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
02:19The Spindle Assembly Checkpoint
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
02:50Spindle Assembly
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
01:16Self-Locking Screw
A square-threaded screw jack is a mechanical device widely used for lifting heavy loads or applying considerable force. One of the key features that can make a screw jack more effective and reliable is its self-locking capability.
A square-threaded screw jack carrying a load is considered self-locking if the screw retains its position even after the moment applied to it is removed.
A square-threaded screw jack carrying a load is considered self-locking if the screw retains its position even after the moment applied to it is removed.
01:19Three-Winding Transformers
Three identical single-phase transformers can be configured to form a three-phase transformer connection, which involves high-voltage and low-voltage windings. The high-voltage windings are denoted by capital letters A-B-C, while the low-voltage windings are labeled with lowercase letters a-b-c, representing their respective phases. This notation helps distinguish between the high and low voltage sides of the transformer.
In the per-unit equivalent circuit of a grounded Y-Y three-phase...
In the per-unit equivalent circuit of a grounded Y-Y three-phase...
01:24Sequence Networks of Rotating Machines
A Y-connected synchronous generator, grounded through a neutral impedance, is designed to produce balanced internal phase voltages with only positive-sequence components. The generator's sequence networks include a source voltage that is exclusively in the positive-sequence network. The sequence components of line-to-ground voltages at the generator terminals illustrate this configuration.
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...