バクテリアのコンデンシン複合体の構造の研究は,ATPに依存した,サブユニット間の相互作用の混乱を明らかにしています

Jae-Sung Woo¹, Jae-Hong Lim, Ho-Chul Shin

¹Center for Biomolecular Recognition and Division of Molecular and Life Science, Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, 790-784, Korea.

Cell

|January 13, 2009

まとめ

バクテリアのコンデンシン複合体MukBEFEF

科学分野:

分子生物学は分子生物学である.
構造生物学構造生物学とは
微生物学微生物学とは

背景:

コンデンシンは,すべての生物における染色体凝縮に責任を負う不可欠なタンパク質複合体です.
細菌のMukBEF複合体は,真核凝縮素の同型であり,SMCタンパク質MukBと,サブユニットMukEとMukFを構成しています.

研究の目的:

MukBEFコンデンシン複合体内の完全な構造的相互作用を解明する.
複合体の機能におけるMukBのATPアゼ活性が果たす役割を調査する.

主な方法:

MukBEF複合体の構造を決定するためのX線結晶学.
MukB.のATPアゼ活性を研究するための生化学分析.
サイト指向型変異遺伝は,特定のドメインとリンクナーの機能を分析するために用いられる.

主要な成果:

完全な構造的な見方は,MukEとMukFが二次元フレームを形成し,MukFのC端の翼状ヘリックス領域 (C-WHDs) がMukBヘッドを結合して環状構造を形成することを明らかにしました.
MukBヘッドのATP媒介による関与は,MukF C-WHDの1つの解離を引き起こし,リング構造を混乱させた.
C-WHDに先立つ左側セグメントの変異は,この脱離を阻害し,細胞の成長を制限しました.

結論:

MukB-MukF相互作用のATP依存的,一時的な障害は,コンデンシン機能の重要な側面です.
コンデンシン環に開口を作り出すこのダイナミックな構造の変化は,MukBEF複合体によって媒介される染色体凝縮に不可欠である可能性が高い.

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