亜鉛GAL4のDNA結合領域の構造

P J Kraulis¹, A R Raine, P L Gadhavi

¹Department of Biochemistry, University of Cambridge, UK.

Nature

|April 2, 1992

まとめ

GAL4タンパク質である.

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
遺伝学遺伝学とは

背景:

イーストのトランスクリプションアクティベーターであるGAL4は,GAL1とGAL10の遺伝子トランスクリプションを調節する.
GAL4には,亜鉛と結合する保存されたシステインに富んだDNA結合ドメインが含まれています.
このドメインの構造は,TFIIIAの亜鉛指に似ていると以前から推測されていた.

研究の目的:

GAL4 DNA結合ドメインの溶液構造を決定する.
GAL4のDNA結合と転写活性化の構造的基礎を解明する.
GAL4の亜鉛結合ドメイン構造を,既知の亜鉛指と受容体DNA結合ドメインと比較する.

主な方法:

1H-113Cd カドミウム結合ドメインの二次元核磁気共鳴 (2D NMR) スペクトロスコピー.
タンパク質の構造モチーフと金属の調整クラスタの分析.
他のDNA結合タンパク質の既存の構造データとの比較.

主要な成果:

GAL4のDNA結合ドメインは,新しい擬似対称構造を採用しています.
2つのヘリックス・ターン・ストランド・モチーフは,Zn2Cys6クラスターの周りに詰め込まれています.
この構造は,TFIIIA型亜鉛指とステロイドホルモン受容体のDNA結合ドメインと大きく異なる.

結論:

GAL4亜鉛結合ドメインは,ユニークな構造の折りたたみを持っています.
この独特の構造が,その特定のDNA結合と転写制御機能の基礎となっている.
この発見は,転写活性化剤における亜鉛結合ドメインの既知の構造的多様性を拡大している.

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