複雑な酵素複合体の存在に関する証拠は,古アルカイア時代には存在していた
Bernd Reisinger1, Josef Sperl, Alexandra Holinski
1Institute of Biophysics and Physical Biochemistry, University of Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany.
Journal of the American Chemical Society
|December 25, 2013
まとめ
研究者は,最後の普遍的共通の祖先 (LUCA) からサイクラスサブユニット (HisF) を再構築しました. この古代の酵素は高い安定性と触媒的活性を示しており,複雑な酵素機能は数十億年前に存在していたことを示唆しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 進化生物学の進化生物学について
- 構造生物学 構造生物学とは
背景:
- マクロ分子化石は存在しないため,絶滅した種の酵素に関する知識は限られている.
- イミダゾルグリセロールリン酸合成酵素 (ImGP-S) 複合体は,代謝経路において極めて重要です.
研究 の 目的:
- 最後の普遍共通祖先 (LUCA) から再構築されたImGP-Sのサイクラスサブユニット (HisF) を特徴付ける.
- 古代酵素の構造的,機能的性質とその進化的起源を理解する.
主な方法:
- LUCA-HisFの結晶構造の決定.
- 触媒活性と熱安定性を評価するための生化学分析.
- 既存のおよび再構築されたHisHサブユニットによる複雑な形成の研究.
主要な成果:
- LUCA-HisFは,現存するHisFタンパク質に似た古代 (βα) 8バレルの折りたたみを持っています.
- この酵素は熱安定性があり,高い触媒活性を示し,HisH.と機能複合体を形成する.
- LUCA-HisFは,再構築されたLUCA-HisHタンパク質に強く結合する.
結論:
- 高効率な酵素や複合体は,基質チャネリングとアロステル通信を含む,LUCA時代 (3.5億年前) に存在していた.
- 酵素の進化は,これまで考えられていたよりもずっと早く,高度な段階に達したのかもしれない.
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