フォスラクトマイシンのcis-Delta ((2,3) - 二重結合は,PKS後の裁縫酵素によって生成されます
Nadaraj Palaniappan1, Mamoun M Alhamadsheh, Kevin A Reynolds
1Department of Chemistry, Portland State University, Portland, OR 97297, USA.
Journal of the American Chemical Society
|August 22, 2008
まとめ
抗真菌フォスラクトマイシン (PLM) は,異例のシス二重結合を有しています. 新しい遺伝子であるplmT2は,cis Delta2,3アルケンの形成に不可欠であり,ポリケチド生物合成に関する新しい洞察を明らかにしています.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 自然製品バイオシンセシス 自然製品バイオシンセシス
背景:
- フォスラクトマイシン (PLM) は,独特のシス二重結合を持つ抗真菌化合物です.
- ポリケチド合成酵素 (PKS) 経路は通常,デヒドラテーズドメインを使用して二重結合を形成します.
- PLMにおけるシスデルタ2,3二重結合の形成は,予測されたPKS脱水酵素ドメインの欠如のために説明できなかった.
研究 の 目的:
- フォスラクトミシンにおけるシスデルタ2,3二重結合の形成のメカニズムを解明する.
- この異常な生物合成のステップに起因する遺伝的要因を特定するために.
- マロニル化ポリケチド製品の生成を理解するために.
主な方法:
- Streptomyces sp.におけるplmT2の遺伝子消去型変異. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803. HK803.
- 分析化学技術を用いた変異株からのPLM製品の分析.
- プラズミドベースのplmT2およびfos ORF4.4の発現を含む補足研究.
- 塩基触媒によるデカルボキシラティブ除去反応の調査.
主要な成果:
- PKS脱水酵素ドメインとのホモロジーがないplmT2遺伝子製品は,効率的なcis Delta2,3アルケンの形成に不可欠です.
- plmT2のデリエーション変異体は,C3ヒドロキシル群を保持したPLM変異体を産生し,それらはマロニル化であった.
- これらのマロニル化中間物質は,塩基触媒によるデカルボキシル化除去により,シスデルタ2,3PLMに変換された.
- 削除変異体におけるplmT2またはfos ORF4の発現により,自然PLM生成が回復した.
結論:
- 脱水酵素系独立経路は,PKS経路の不飽和ラクトン部分にシス二重結合を確立することができます.
- plmT2遺伝子産物は,ポリケチド生物合成における新しい因子である.
- この研究は,異常なマロニル化ポリケチド産物の形成に関する最初の生物合成の洞察を提供します.
- この発見は,ポリケチド天然産物バイオシンセシスの多様性とメカニズムについての理解を広げています.
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