核型60S前リボソームサブユニットのモジュール組成

Zahra Assur Sanghai¹, Linamarie Miller^1,2, Kelly R Molloy³

¹Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, New York 10065, USA.

Nature

|March 8, 2018

まとめ

初期ユカリオットのリボソーム組成に関する構造的な洞察は,21の要因が早めの折り畳みを防ぐことを明らかにしています. クリオ電子顕微鏡 (cryo-EM) は,単方向の生体生成を誘導する60S前核子構成を可視化します.

科学分野:

分子生物学
構造生物学
細胞生物学

背景:

ユカリオットリボソームの組み立てには,複雑な共同転写イベントと多数の一時的な要因が含まれます.
初期の核性60Sサブユニット成熟における組み立て因子の正確な役割は,構造データが限られているため,まだよく理解されていません.

研究の目的:

早期の核性60Sリボソームサブユニット組成を制御する構造的メカニズムを解明する.
リボソーム前RNAの折りたたみと粒子の構造を導くためのリボソーム組立因子の機能を理解する.

主な方法:

クリオ電子顕微鏡 (cryo-EM) を用いて,核型60Sリボソームサブユニットの高解像度構造を決定した.
60S前粒子の複数の構成状態の分析

主要な成果:

Cryo-EM再構築では,21の組立因子によるステリック阻害と分子模倣が,早めの折り畳みと因子結合を防ぐことが明らかになった.
3つのブリックスドメインのタンパク質とパートナーはリング構造を形成し,rRNAドメインの境界を安定させます.
相互排他的形状は,ポリペプチドの脱出トンネルのための代替の折り畳み経路を示唆する.

結論:

この研究は,単方向性ユーカリオットリボソームの生体生成を推進するアセンブリ因子の協調的作用の構造的証拠を提供します.
これらの発見は,既存の遺伝学および生化学データを合理化し,リボソームの組み立てに関するメカニズム的な洞察を提供します.

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