拡張中間状態のテトラメリック MscL の構造
Zhenfeng Liu1, Chris S Gandhi, Douglas C Rees
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Nature
|August 25, 2009
まとめ
研究者らは,細菌の機械感受性チャンネル (MscL) 変異体の構造を決定した. この構造は中間状態を明らかにし,これらの重要な細胞ゲートが機械的ストレス下でどのように機能するかについての洞察を提供します.
科学分野:
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
- 構造生物学 構造生物学とは
背景:
- 細胞のメカノセンセーションは,触覚,聴覚,バクテリアのオスモレギュレーションなどのプロセスに不可欠です.
- メカノセンシティブチャネル (MSC) は,細胞圧力を放出することによって,細菌を溶解から保護します.
- 大伝導性の機械感受性チャンネル (MscL) は,重要な細菌MSCですが,その中間ゲーティング状態は十分に理解されていません.
研究 の 目的:
- MscLゲーティングメカニズムの構造的基礎を明らかにする.
- X線結晶学を用いて MscL の中間状態を特徴付ける.
- MscL.の複雑なゲーティング行動に関する構造的な洞察を提供するためです.
主な方法:
- X線結晶学を用いて,Staphylococcus aureus MscL (SaMscL) のカーボキシ末端切断変異体 (SaMscL ((CDelta26)) の構造を決定した.
- 結晶構造は3.8 Åの解像度で解明されました.
- 構造分析は,トランスメブランヘリクと全体的なチャネルアセンブリの構成に焦点を当てました.
主要な成果:
- 結晶構造は,テトラメリック SaMscL ((CDelta26) チャンネルを明らかにした.
- トランスメブランヘリクスが傾斜し,膜の正常状態から逸脱していることが観察されました.
- この形状は, MscL.の部分的に膨張した,伝導性のない中間状態を示唆しています.
結論:
- 判定された構造は,MscL.の新しい中間形状を表しています.
- この発見は,MscLゲーティング経路に関する私たちの理解を前進させます.
- 中間状態に関する構造的データは, MscL 機能の完全な特徴化に不可欠です.
関連する概念動画
Predicting Molecular Geometry
VSEPR Theory for Determination of Electron Pair Geometries
Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Fluid Mosaic Model
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich with the analogy of...
The Inner Mitochondrial Membrane
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
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...
Structure of Cadherins
The cadherins were one of the first cell adhesion molecules discovered; the term “cadherins” is based on their calcium-dependent adhering properties. The first cadherins discovered on the epithelial, neuronal, and placental cells were named E-cadherin, P-cadherin, and N-cadherin, respectively. These classical cadherins share sequence and structural similarities. Other cadherins, including those involved in cell signaling, are grouped into non-classical cadherins. This diversity of cadherins...


