Li Jingru, Jensen Susan E
Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada.
Chem Biol. 2008 Feb;15(2):118-27. doi: 10.1016/j.chembiol.2007.12.014.
Paenibacillus polymyxa PKB1 produces fusaricidins, a family of lipopeptide antibiotics that strongly inhibits the growth of many plant pathogenic fungi. The fusaricidin biosynthetic gene cluster was cloned and sequenced, and it spans 32.4 kb, including an open reading frame (fusA) encoding a six-module nonribosomal peptide synthetase. The second, fourth, and fifth modules of fusaricidin synthetase each contain an epimerization domain, consistent with the structure of fusaricidins. However, no epimerization domain is found in the sixth module, corresponding to D-Ala. This sixth adenylation domain was produced at a high level in Escherichia coli and is shown to activate D-Ala specifically, providing evidence for direct activation of a D-amino acid by a prokaryotic peptide synthetase. The fusaricidin gene cluster also includes genes involved in the biosynthesis of the lipid moiety, but no genes for resistance, regulation, or transport functions were encountered.
多粘类芽孢杆菌PKB1产生多杀霉素，这是一类脂肽抗生素，能强烈抑制多种植物病原真菌的生长。多杀霉素生物合成基因簇被克隆并测序，其跨度为32.4 kb，包括一个编码六模块非核糖体肽合成酶的开放阅读框（fusA）。多杀霉素合成酶的第二、第四和第五模块各包含一个差向异构化结构域，这与多杀霉素的结构一致。然而，在对应于D-丙氨酸的第六模块中未发现差向异构化结构域。该第六腺苷化结构域在大肠杆菌中高水平产生，并显示出特异性激活D-丙氨酸，为原核肽合成酶直接激活D-氨基酸提供了证据。多杀霉素基因簇还包括参与脂质部分生物合成的基因，但未发现抗性、调控或转运功能的基因。
