メタンを無酸素で酸化する黒海マットからのメチル-コエンザイムM還元酵素の構造
Seigo Shima1, Martin Krueger, Tobias Weinert
1Max Planck Institute for Terrestrial Microbiology, Karl-Frisch-Strasse 10, D-35043 Marburg, Germany. shima@mpi-marburg.mpg.de
Nature
|November 29, 2011
まとめ
研究者らは,メタン (AOM) の無酸素酸化におけるメタン活性化酵素の構造を明らかにした. この酵素,ANME-1 MCRは,メタノゲン同位体と基板を共有していますが,特徴は異なります.
科学分野:
- 微生物学と生化学について
- 構造生物学 構造生物学とは
- バイオジオケミストリー バイオジオケミストリー
背景:
- メタン (AOM) を硫酸塩で無酸素酸化することは,無酸素メタノトロフィックアーカイア (ANME) と硫酸塩を減少させる細菌のコンソーシアムによって推進される重要な微生物のプロセスです.
- ANMEアーカイアにおけるメタン活性化に責任を負う酵素は,メタノゲン性アーカイアにも存在するメチル-共酵素M還元酵素 (MCR) のホモログであると考えられています.
研究 の 目的:
- ANME-1 MCR複合体のX線構造を決定するために.
- AOMにおけるメタンの活性化の構造的基礎を理解する.
- ANME-1のMCRとメタノゲン系アーカイアからのMCRを比較する.
主な方法:
- 黒海から収集された微生物コンソーシアムからANME-1 MCRの浄化.
- 280 kDaのヘテロヘクサメリクスのANME-1 MCR複合体の結晶化.
- 2.1 Å の解像度で構造を決定するX線 difraktion 分析.
主要な成果:
- ANME-1 MCR複合体のX線構造が成功裏に決定されました.
- ANME-1 MCRは,その基質であるコエンザイムMおよびコエンザイムBとの複合体であることが判明しました.
- メタノゲン性MCRと比較して重要な構造的な違いが特定されましたが,その中には,F430の改変,システインに富んだパッチ,および変異した翻訳後の改変が含まれています.
結論:
- この研究は,ANMEアーカイアからのメタン活性化酵素に関する最初の構造的洞察を提供します.
- 特定された構造的変異は,ANME-1 MCRのAOMにおける役割に適応することを示唆しています.
- これらの発見は,微生物のメタンサイクルと酵素の進化に関する私たちの理解を前進させます.
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