Jin Mi, Fischbach Michael A, Clardy Jon
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
J Am Chem Soc. 2006 Aug 23;128(33):10660-1. doi: 10.1021/ja063194c.
Increasing bacterial resistance to antibiotics with conventional targets has focused attention on antibiotics with unconventional targets. One promising candidate, the acetyl-CoA carboxylase (ACC) inhibitor andrimid, is a potent, broad-spectrum antibiotic with high selectivity for prokaryotic ACC. Here, we report the use of a DNA-based approach to clone the andrimid biosynthetic gene cluster from Pantoea agglomerans, yielding a cosmid that confers robust andrimid production on Escherichia coli. This gene cluster encodes a hybrid nonribosomal peptide/polyketide (NRP/PK) synthase with several unusual features, including three enzymes that form and insert beta-phenylalanine, two transglutaminase-like enzymes that likely serve as condensation catalysts, and four densely hybrid modules that form the succinimide precursor. Unlike most type I NRPSs and PKSs, the andrimid gene cluster is a dissociated system comprised of small proteins. Therefore, future efforts can exploit the genetic manipulability of E. coli to engineer the andrimid synthase with the goal of producing a diverse set of andrimid analogues for clinical evaluation.
细菌对具有传统作用靶点的抗生素的耐药性不断增加，这使得人们将注意力集中在具有非传统作用靶点的抗生素上。一种有前景的候选药物，即乙酰辅酶A羧化酶（ACC）抑制剂抗霉素，是一种对原核ACC具有高选择性的强效广谱抗生素。在此，我们报告了一种基于DNA的方法，用于从成团泛菌中克隆抗霉素生物合成基因簇，得到一个能使大肠杆菌大量产生抗霉素的黏粒。该基因簇编码一种具有几个不同寻常特征的杂合非核糖体肽/聚酮合酶（NRP/PK），包括三种形成并插入β-苯丙氨酸的酶、两种可能作为缩合催化剂的转谷氨酰胺酶样酶，以及四个形成琥珀酰亚胺前体的紧密杂合模块。与大多数I型NRPS和PKS不同，抗霉素基因簇是一个由小蛋白组成的解离系统。因此，未来的研究可以利用大肠杆菌的遗传可操作性来改造抗霉素合酶，目标是生产出一系列用于临床评估的抗霉素类似物。
