酵母DNAポリメラーゼゼータゼータによるチミン・チミン・ダイマーバイパス

J R Nelson¹, C W Lawrence, D C Hinkle

¹Department of Biophysics, School of Medicine and Dentistry, University of Rochester Medical Center, New York 14642, USA.

Science (New York, N.Y.)

|June 14, 1996

まとめ

REV3とREV7遺伝子は酵母DNA修復に不可欠です. 彼らのタンパク質複合体であるDNAポリメラーゼゼータは,他のポリメラーゼとは異なり,DNA損傷を効率的に回避します.

科学分野:

分子生物学は分子生物学である.
遺伝学遺伝学とは
バイオケミストリーバイオケミストリー

背景:

DNAの損傷は複製を阻害し,突然変異を引き起こす可能性があります.
Saccharomyces cerevisiaeのREV3およびREV7のような特定の遺伝子は,DNA損傷耐性に関与しています.
DNA修復と突然変異のメカニズムを理解することは,細胞の健康に不可欠です.

研究の目的:

DNA損傷による突然変異におけるREV3とREV7の役割を調査する.
Rev3-Rev7タンパク質複合体の酵素活性を特徴付けるために.
Rev3-Rev7複合体によるDNA損傷バイパスの効率を他のDNAポリメラーゼと比較する.

主な方法:

酵母におけるREV3およびREV7遺伝子の遺伝子解析.
Rev3-Rev7タンパク質複合体の生化学的浄化と特徴付け.
チミン・チミン・シス・シン・サイクロブタン・ジマーを含むDNAテンプレートを用いたインビトロ複製アッセイ.

主要な成果:

Rev3-Rev7タンパク質は,DNAポリメラーゼ活性を持つ複合体を形成する.
DNAポリメラーゼゼータとして識別されたこの複合体は,約10%の効率で,過去チミン-チミンダイマーを複製しました.
イーストDNAポリメラーゼアルファは,同じ病変のバイパス効率 (≤1%) を著しく低下させた.

結論:

Rev3-Rev7複合体,DNAポリメラーゼゼータは,DNA損傷による病変をバイパスする上で重要な役割を果たしています.
DNAポリメラーゼゼタは,DNAポリメラーゼアルファよりも,トランスレション合成においてより効率的です.
この発見は,DNA損傷後のゲノム整合性の維持に関与する新しい真核DNAポリメラーゼを特定しています.

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