微信E492m的生物合成定制:翻译后的修改提供了抗菌的 siderophore-peptide 结合体
Elizabeth M Nolan1, Michael A Fischbach, Alexander Koglin
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Journal of the American Chemical Society
|November 2, 2007
概括
四种蛋白质修改了微信E492 (MccE492),这是来自Klebsiella pneumoniae的毒素. 它们将一种修改后的肠杆菌素 (铁除菌素) 附着在MccE492上,从而产生一种强大的抗菌剂.
科学领域:
- 微生物学 微生物学
- 生物化学 生物化学
- 分子生物学分子生物学
背景情况:
- 克莱布西拉肺炎RYC492分泌微E492 (MccE492),这是一个84残留蛋白质毒素,向格拉姆阴性细菌.
- MccE492经历了广泛的翻译后修改,以达到其成熟,活跃的形式,MccE492m.
研究的目的:
- 阐明负责MccE492.4的翻译后修改的分子机制和蛋白质机制.
- 描述涉及肠杆菌素衍生物化及其随后与MccE492.492的附着的酶性步骤.
主要方法:
- 对MccE492基因集群进行基因分析,以识别修饰蛋白 (MceCDIJ).
- 生物化学测试以确定MceC,MceD,MceI和MceJ的酶活性.
- 使用分析技术,对改性肠杆菌素及其与MccE492的联系进行表征.
主要成果:
- MceCDIJ蛋白质复合体负责MccE492.2的翻译后定制.
- MceC和MceD酶通过C-糖化和水解来改变肠杆菌素.
- MceI和MceJ复合物将修改后的肠杆菌素连接到MccE492的C端,在非酶性重新排列后形成C6'甘酸链接.
结论:
- MceCDIJ蛋白对于产生成熟的,有毒的MccE492.2形式至关重要.
- 这项研究揭示了 siderophore 与毒素结合的新奇机制.
- 了解这些修改可以了解细菌毒素的产生和潜在的抗微生物点.
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