転写精度因子 GreA は DNA 断裂修復を阻害する

Priya Sivaramakrishnan¹, Leonardo A Sepúlveda², Jennifer A Halliday¹

¹Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

Nature

|October 5, 2017

まとめ

転写因子 GreA は,E. coli の DNA 断裂修復を阻害する. その欠如は,RNAポリメラーゼのバックトラッキングを促し,再結合を促進します.

科学分野:

分子生物学
遺伝学
微生物学

背景:

複製されたDNAでも DNAの二重鎖の断裂を修復するためにホモログの再結合が不可欠です
DNA断裂修復と転写プロセシビティの相互作用は,まだ完全に理解されていません.
ゲノムの整合性を維持することは極めて重要ですが複製の精度とのバランスは複雑です

研究の目的:

エシェリキア・コロイにおけるDNA二重鎖破裂修復における GreA 転写因子の役割を調査する.
転写忠誠度,RNAポリメラーゼの逆行,および同類再結合の相互作用を解明する.
GreAがRecBCD-RecA修復経路にどのように影響するか理解する.

主な方法:

染色体外核分解を定量化するために深層配列化を使用した.
野生型とGreA欠乏菌株のEscherichia coliのDNA破裂修復効率を評価した.
RecAの負荷と再結合に対するRNAポリメラーゼのバックトラッキングの影響を分析した.

主要な成果:

GreAの欠如は,RecBCD-RecA経路経由による同類再結合を著しく強化する.
GreA欠乏は,RecBCD媒介のDNA切除を制限し,修復を制御する役割を示唆する.
GreA欠乏細胞におけるRNAポリメラーゼのバックトラッキングの増加は,Chiサイトとは独立してReCAの負荷を促進する.

結論:

GreAは,トランスクリプションフィデリティファクターで,E. coliのDNA破裂修復を阻害する.
GreAの欠如によって刺激されるRNAポリメラーゼのバックトラッキングは,同種の再結合を促進する.
これはトランスクリプションの正確性を促進する要因がゲノムの完全性を損なうパラドックスを強調しています

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