バクテリアのペプチドグリカン生物合成のためのグリコペプチジルグルタマートエピメラーゼ
Ruoyin Feng1, Yasuharu Satoh2, Yasushi Ogasawara2
1Graduate School of Chemical Sciences and Engineering, Hokkaido University , N13 & W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan.
Journal of the American Chemical Society
|March 16, 2017
まとめ
Xanthomonas oryzaeはペプチドグリカン生物合成のための新しい酵素を有し,ユニークなMurD結合L-グルタミン酸とそれをD-グルタミン酸 (d-Glu) に変換するエピメラーゼを含む. これらの発見は,微生物におけるd-Gluの代替経路を示しています.
科学分野:
- 微生物学
- 生物化学
- 分子生物学
背景:
- 微生物はペプチドグリカン生物合成のためにd-グルタマート (d-Glu) を利用し,通常はGluレースマースまたはd-アミノ酸トランスアミナーゼを介して.
- 比較ゲノミクスは,Xanthomonas oryzaeのようないくつかの細菌は,これらの既知のd-Glu合成経路が欠けていることを示唆しています.
研究 の 目的:
- Xanthomonas oryzaeのd-Glu代謝に関与する新しい遺伝子を特定し,特徴づけること.
- ペプチドグリカン生物合成に不可欠な新発見遺伝子の酵素機構と基板を解明する.
主な方法:
- ショットガンのクローン 宿主としてd-Gluオックストロフィックエシェリキア・コーライ変異体
- サブストラット特異性と反応産物を決定するインビトロ酵素測定
- 比較ゲノミクスは,特定された遺伝子の微生物種間の分布を調査する.
主要な成果:
- XOO_1319とXOO_1320という2つの遺伝子は,X. oryzaeからクローンされました.
- XOO_1320はMurd酵素として機能し,L-グルタミン酸 (l-Glu) をUDP-MurNAc-l-Alaに唯一結合する.
- XOO_ 1319は,ATPとMg2+の存在下で端末のl-Gluをd-Gluに変換する新種のエピメラーゼです.
結論:
- Xanthomonas oryzaeは,新しいL-Glu利用のMurDとエピメラーゼを含む,異なるd-Glu合成経路を使用しています.
- 特定された酵素は,d-Gluをペプチドグリカンに組み込むための新しいメカニズムを表しています.
- XOO_1319のオートロゲンは,病原性種を含む様々な微生物で発見され,より広範な影響を示唆しています.
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