罗利兹维林,一种独特的细菌类化合物,由非核糖体合成酶和非酶体二分化组装在一起
Juliana Effert1, Margaretha Westphalen2, Andrea Calderari3
1Max Planck Institute for Terrestrial Microbiology, Department of Natural Products in Organismic Interactions, 35043, Marburg, Germany.
Angewandte Chemie (International ed. in English)
|October 20, 2024
概括
这项研究通过识别Xenorhabdus hominickii中的新型基因集群,阐明了pyrrolizidine类化合物 (PAs) 的细菌生物合成,特别是伪二次体pyrrolizwilline. 研究人员详细介绍了该途径并描述了关键酶的特征,进步了我们对复杂细菌PA生产的理解.
科学领域:
- 微生物学 微生物学
- 自然产品生物合成 自然产品生物合成
- 生物化学 生化学
背景情况:
- 罗利胺类化合物 (PAs) 已因其在植物中的毒性而闻名,但它们在细菌生物合成和作用的理解较少.
- 植物PA生物合成涉及同性氨酸合成酶,而细菌途径利用非核糖体合成酶和单氧基酶.
- 复杂的细菌PA及其生物功能在很大程度上仍未被描述.
研究的目的:
- 为了识别和表征负责产生PA伪二极体pyrrolizwilline的细菌基因集群.
- 为了阐明 pyrrolizwilline 在 Xenorhabdus hominickii 的详细生物合成途径.
- 描述参与罗利兹维林形成的关键酶XhpG.
主要方法:
- 在Xenorhabdus hominickii中识别和分析xhpA-G基因集群.
- 在X. hominickii中促进物交换突变发生和在E. coli中异质表达.
- 途径中间体的化学合成和衍生物的表征.
- 用X射线结晶学和小角度X射线散射 (SAXS) 来进行酶特性鉴定.
主要成果:
- 鉴定出了xhpA-G基因集群是负责罗利兹威林生产的.
- 提出了一个详细的生物合成途径,以pyrrolizwilline,由识别的中间体和衍生品支持.
- 鉴定了XhpG酶的特征,揭示了它在将pyrrolizixenamide转化为pyrrolizwilline中的关键作用.
结论:
- 已经阐明了一个新的细菌途径,用于pyrrolizidine化物生物合成.
- 这项研究提供了对复杂细菌PA的产生有意义的见解.
- 对XhpG的表征提供了理解这一关键酶化步骤的结构基础.
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