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テトラヒメナ・リボ酵素の結晶構造における事前組織された活性部位
B L Golden1, A R Gooding, E R Podell
1Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215, USA. bgolden@petunia.colorado.edu
Science (New York, N.Y.)
|December 5, 1998
まとめ
グループIのイントロンは,自己結合する触媒RNAである. Tetrahymena thermophila group I intron ribozymeの結晶構造は,タンパク質酵素に類似した基板のための事前組織された結合部位を明らかにしています.
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
- バイオケミストリー バイオケミストリー
背景:
- グループIのイントロンは,自己スプライシングで知られている触媒性RNA分子です.
- 一つの活性部位内で2つの連続した反応を触媒化する.
研究 の 目的:
- Tetrahymena thermophilaグループIの結晶構造を決定するために,イントロン触媒コア.
- このリボ酵素における基板結合と前組織化の構造的基礎を理解する.
主な方法:
- X線結晶学を用いて5.0アングストームの構造を決定した.
- この研究は,2つの活性ドメインを含む247ヌクレオチドリボ酵素に焦点を当てた.
主要な成果:
- 結晶構造は,2つのドメインの密接な包装を明らかにし,5'スプライスサイト結合のための裂け目を形成します.
- グアノシン基板のための明確な結合ポケットは,A型幾何学から逸脱する.
- これらの結合ポケットは,基板の結合の前に,前編成され,指向されます.
結論:
- Tetrahymena thermophila群Iイントロンリボ酵素は,大部分が触媒作用のために前編成されている.
- この事前組織化は,球状タンパク質酵素の構造的特徴に類似しています.
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