二核Fe(III) -Zn(II) 活性部位を含む紫酸ファスファターゼの結晶構造
N Sträter1, T Klabunde, P Tucker
1Anorganisch-Chemisches Institut, Universität Münster, Germany.
Science (New York, N.Y.)
|June 9, 1995
まとめ
腎豆紫酸ホスファターゼ (KBPAP) は,Fe (III) - Zn (II) 酵素である. その構造は,リン酸エステル水解機構の理解に不可欠な活性部位の詳細を明らかにします.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- 酵素学 酵素学とは
背景:
- 腎豆紫酸ホスファターゼ (KBPAP) は,Fe (III) - Zn (II) 金属酵素である.
- 哺乳類の紫酸リン酸塩酸相と構造的,機能的な類似性を共有しています.
研究 の 目的:
- KBPAPの高解像度の3次元構造を決定する.
- アクティブサイトアーキテクチャと金属イオン協調を明らかにする.
主な方法:
- X線結晶学を用いて,同型KBPAPの構造を決定した.
- 構造は2.9アングストロムの解像度で解像させられました.
主要な成果:
- ホモディメール111キロダルトンのKBPAP構造が解明されました.
- 活性部位には,2つの金属イオン (Fe (III) と Zn (II)) がAsp164.4によって橋渡されている.
- 特定のアミノ酸残基は,Tyr167,His325,Asp135,His286,His323,およびAsn201を含む金属イオンを調整する.
結論:
- 決定された活性サイト構造は,リン酸エステル水解の提案されたメカニズムをサポートしています.
- この発見は,フォスファートエステルに対する核愛性の攻撃におけるFe (III) -調整されたヒドロキシドイオンの役割を強調しています.
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