Abstract:
Chalkophomycin is a novel chalkophore with antibiotic activities isolated from Streptomyces sp. CB00271, while its potential in studying cellular copper homeostasis makes it an important probe and drug lead. The constellation of N-hydroxylpyrrole, 2H-oxazoline, diazeniumdiolate, and methoxypyrrolinone functional groups into one compact molecular architecture capable of coordinating cupric ions draws interest to unprecedented enzymology responsible for chalkophomycin biosynthesis. To elucidate the biosynthetic machinery for chalkophomycin production, the chm biosynthetic gene cluster from S. sp. CB00271 was identified, and its involvement in chalkophomycin biosynthesis was confirmed by gene replacement. The chm cluster was localized to a ~31 kb DNA region, consisting of 19 open reading frames that encode five nonribosomal peptide synthetases (ChmHIJLO), one modular polyketide synthase (ChmP), six tailoring enzymes (ChmFGMNQR), two regulatory proteins (ChmAB), and four resistance proteins (ChmA\'CDE). A model for chalkophomycin biosynthesis is proposed based on functional assignments from sequence analysis and structure modelling, and is further supported by analogy to over 100 chm-type gene clusters in public databases. Our studies thus set the stage to fully investigate chalkophomycin biosynthesis and to engineer chalkophomycin analogues through a synthetic biology approach.
摘要:
Chalkophomycin是从链霉菌属中分离出的具有抗生素活性的新型Chalkophore。CB00271,而其在研究细胞铜稳态方面的潜力使其成为重要的探针和药物先导。N-羟基吡咯的星座,2H-恶唑啉,dianolate二氮烯胺,和甲氧基吡罗啉酮官能团形成一个能够协调铜离子的紧凑分子结构,引起了前所未有的酶学研究的兴趣,该酶学负责白垩霉素的生物合成。为了阐明用于生产白垩霉素的生物合成机制,来自S.sp.的chm生物合成基因簇。CB00271被识别,并通过基因置换证实了其参与白垩霉素的生物合成。chm簇位于约31kb的DNA区域,由19个开放阅读框组成,编码五种非核糖体肽合成酶(ChmHIJLO),一种模块化聚酮合成酶(ChmP),六种剪裁酶(ChmFGMNQR),两种调节蛋白(ChmAB),和四种抗性蛋白(ChmA/CDE)。基于序列分析和结构建模的功能分配,提出了一种黄色霉素生物合成模型,并通过类比公共数据库中超过100个chm型基因簇得到进一步支持。因此,我们的研究为充分研究黄体霉素的生物合成和通过合成生物学方法设计黄体霉素类似物奠定了基础。