触媒の歪み:エシェリキア大腸チオレドキシン還元酵素の交替する形状
B W Lennon1, C H Williams, M L Ludwig
1Biophysics Research Division, Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
Science (New York, N.Y.)
|August 19, 2000
まとめ
エシェリキア大腸菌のチオレドキシン還元酵素 (TrxR) は,フラビンアデニンジヌクレオチド (FAD) の還元と再酸化のためにドメインの再編成を経験します. 3.0アングストームの構造は,NADPHによるFAD減少を可能にするフラビン還元形状を明らかにします.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- 酵素学 酵素学とは
背景:
- エシェリキア大腸菌からのチオレドキシン還元酵素 (TrxR) は,フラビンアデニンジヌクレオチド (FAD) のコファクターを使用します.
- 酵素活性には,ドメインの再編成に依存するFADの周期的還元と再酸化が含まれています.
研究 の 目的:
- E. coli TrxR.におけるフラビン減少の構造的基礎を解明する.
- E. coli TrxR.のフラビン還元形状を特徴づけるために
主な方法:
- 3.0アングストームの解像度のX線結晶学.
- 異なる酵素構成の構造的比較.
主要な成果:
- E. coli TrxRのフラビン還元型構造の構造が決定されました.
- この形状は,NADPHによるFAD還元と,チオレドキシンによるディチオール酸化を可能にします.
- 別の形状と比較すると,ピリジンの核酸結合ドメインの67度回転が示され",球とソケット"運動と表現されています.
結論:
- ドメインの再編成は,E. coli TrxR.R.の触媒サイクルにとって極めて重要です.
- 特定されたフラビン還元形状は,FAD還元およびその後の酵素反応のメカニズムを洞察します.
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