一种用于细菌甘油生物合成的糖基胺酶
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
概括
克桑托莫纳斯菌具有用于糖生物合成的新型酶,包括独特的MurD结合L-谷氨酸和将其转化为D-谷氨酸 (d-Glu) 的表皮酶. 这些发现揭示了d-Glu在微生物中的替代途径.
科学领域:
- 微生物学
- 生物化学
- 分子生物学
背景情况:
- 微生物利用d-glutamate (d-Glu) 进行糖生物合成,通常通过Glu种族酶或d-氨基酸转氨酶.
- 比较基因组学表明一些细菌,如Xanthomonas oryzae,可能缺乏这些已知的d-Glu合成途径.
研究的目的:
- 鉴定和描述参与Xanthomonas oryzae中d-Glu代谢的新基因.
- 阐明新发现的糖生物合成关键基因的酶机制和基底.
主要方法:
- 使用大肠杆菌突变体作为宿主.
- 在体外酶测试以确定基质特异性和反应产物.
- 进行比较基因组学,以研究已识别的基因在微生物物种中的分布.
主要成果:
- 两个基因,XOO_1319和XOO_1320,是从X. oryzae中克隆的.
- 作为一个MurD酶,XOO_1320将L-氨酸 (l-Glu) 单独结合到UDP-MurNAc-l-Ala.
- 在ATP和Mg2+的存在下将终端l- Glu转化为d- Glu的新型表皮酶.
结论:
- Xanthomonas oryzae采用一种独特的d-Glu合成途径,涉及一种新的L-Glu利用的MurD和一个表皮酶.
- 这些已识别的酶代表了d-Glu被纳入糖的新机制.
- 在包括致病物种在内的各种微生物中发现了XOO_1319的正方体,这表明了更广泛的含义.
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