The barbamide biosynthetic gene cluster: a novel marine cyanobacterial system of mixed polyketide synthase (PKS)-non-ribosomal peptide synthetase (NRPS) origin involving an unusual trichloroleucyl starter unit
The barbamide biosynthetic gene cluster: a novel marine cyanobacterial system of mixed polyketide synthase (PKS)-non-ribosomal peptide synthetase (NRPS) origin involving an unusual trichloroleucyl starter unit
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DOI：
10.1016/s0378-1119(02)00860-0
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发表时间：
2002-08-21
期刊：
影响因子：
3.5
通讯作者：
Sherman, DH
中科院分区：
文献类型：
--
作者：
Chang, ZX;Flatt, P;Sherman, DH
从海洋蓝藻Lyngbya Majuscula菌株19L中提取了具有较强杀螺活性的氯化脂肽。前体掺入研究表明，它来源于乙酸酯、L-苯丙氨酸、L-亮氨酸和L-半胱氨酸。本研究克隆并鉴定了与巴拉巴胺生物合成相关的基因簇。对粘粒pLM49的DNA序列分析显示，pLM49的12个开放阅读框(Bara-bark)长达26kb，包括预期的聚酮合成酶和非核糖体多肽合成酶模块以及剪裁基因。BAR集群的遗传架构和域组织支持基于系统的明显共线性进行分配。通过对BARD(A(D))、Bare(A(E))和Barg(A(G2)的腺基化结构域的活性测定，证实了BARD(A(D))、Bare(A(E))和Barg(A(G2))是由醋酸酯、L-苯丙氨酸、L-半胱氨酸和L-亮氨酸以三氯亮氨酸为直接前体，在聚酮合成酶/非核糖体多肽合成酶的作用下合成的。巴巴胺的组装包括独特的氯化、链延伸过程中的一碳截断、E-双键形成和噻唑环形成等独特的生化机制。(C)2002 Elsevier Science B.V.保留所有权利。
Barbamide was extracted from the marine cyanobacterium Lyngbya majuscula strain 19L as a chlorinated lipopeptide for its potent molluscicidal activity. Precursor incorporation studies indicated that it is derived from acetate, L-phenylalanine, L-leucine and L-cysteine. The gene cluster responsible for biosynthesis of barbamide (bar) was cloned and characterized in this study. DNA sequence analysis of cosmid pLM49 revealed a cluster of 12 open reading frames (barA-barK) extending 26 kb including the expected polyketide synthase and non-ribosomal peptide synthetase modules and tailoring genes. The genetic architecture and domain organization of the bar cluster supports the assignment based on the apparent co-linearity of the systems. The activity assay of adenylation domains of barD (A(D)), barE (A(E)) and barG (A(G2) for module 2) in an amino acid-dependent ATP-pyrophosphate exchange experiment supports the conclusion that barbamide is synthesized from acetate, L-phenylalanine, L-cysteine and L-leucine with trichloroleucine as a direct precursor by a mixed polyketide synthase/non-ribosomal polypeptide synthetase. Assembly of barbamide includes unique biochemical mechanisms for chlorination, one-carbon truncation during chain elongation, E-double bond formation and thiazole ring formation. (C) 2002 Elsevier Science B.V. All rights reserved.