脂肪アシルの認識と統合膜S-アシルトランスファーゼによる転送
Mitra S Rana1, Pramod Kumar1, Chul-Jin Lee1
1Cell Biology and Neurobiology Branch, National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
まとめ
DHHCパルミトイルトランスフェラーゼは,細胞シグナル伝達における重要な酵素である. 構造的な洞察は,膜-細胞溶液界面での活性部位を明らかにし,基板特異性を説明し,将来の薬剤設計を導く.
科学分野:
- 生物化学
- 構造生物学
- 酵素学
背景:
- DHHC (Asp-His-His-Cys) パルミトイルトランスフェラーゼは,エウカリオットの欠かせない膜酵素である.
- タンパク質のパルミトイレーションを触媒化し,これは翻訳後の重要な変化です.
- Palmitoylationは,GTPaseシグナル伝達,細胞結合,受容体構造などの重要な細胞プロセスを調節する.
研究 の 目的:
- DHHC パルミトイルトランスフェラーゼの活性に関する構造的基礎を解明する.
- タンパク質のパルミトイレーションの仕組みを理解する
- アシル鎖の長さの選択性の決定要因を調査する.
主な方法:
- 2つのDHHCパルミトイルトランスファーゼの構造を決定するために,X線結晶学を用いた.
- コヴァレントの中間ミミクも結晶化した.
- アチル鎖結合腔に変異性研究が行われました.
主要な成果:
- 結晶構造は 膜細胞界面にある活性部位を明らかにした.
- アシル鎖は,トランスメブラン領域によって形成された空洞の中で結合する.
- 変異した酵素は,より短く,より長い脂肪アシル共酵素A鎖を好む傾向を示した.
結論:
- 活性部位の位置はチオエステル交換化学を容易にする.
- トランスメブランドメインの穴は,アシル鎖の長さの選択性を決定する.
- これらの発見は,DHHCパルミトイレーションのメカニズムの理解を提供します.
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