Cloning and identification of saprolmycin biosynthetic gene cluster from <i>Streptomyces</i> sp. TK08046

Saprolmycins A–E are anti-<i>Saprolegnia parasitica</i> antibiotics. To identify the gene cluster for saprolmycin biosynthesis in <i>Streptomyces</i> sp. TK08046, polymerase chain reaction using aromatase and cyclase gene-specific primers was performed; the <i>spr</i> gene cluster, which codes for angucycline biosynthesis, was obtained from the strain. The cluster consists of 36 open reading frames, including minimal polyketide synthase, ketoreductase, aromatase, cyclase, oxygenase, and deoxy sugar biosynthetic genes, as defined by homology to the corresponding genes of the urdamycin, Sch-47554, and grincamycin biosynthetic gene clusters in <i>Streptomyces fradiae</i>, <i>Streptomyces</i> sp. SCC-2136, and <i>Streptomyces lusitanus</i>, respectively. To establish the function of the gene cluster, an expression cosmid vector containing all 36 open reading frames was introduced into <i>Streptomyces lividans</i> TK23. The transformant was confirmed to express the biosynthetic genes and produce saprolmycins by liquid chromatography–mass spectrometry analysis of the extract. We identified and cloned a <i>spr</i> gene cluster, which is involved in the biosynthesis of saprolmycin, and succeeded in heterologous production of saprolmycin.

腐霉霉素A~E（saprolmycins A–E）是抗寄生水霉（Saprolegnia parasitica）的抗生素。为鉴定链霉菌（Streptomyces）sp. TK08046中腐霉霉素的生物合成基因簇，研究人员采用针对芳香化酶与环化酶基因的特异性引物开展聚合酶链式反应（polymerase chain reaction，PCR），最终从该菌株中获得了编码安哥拉霉素（angucycline）生物合成的spr基因簇。该基因簇共包含36个开放阅读框（open reading frames，ORF），涵盖最小聚酮合酶、酮还原酶、芳香化酶、环化酶、氧化酶以及脱氧糖生物合成相关基因，上述基因的界定基于与分别来自弗氏链霉菌（Streptomyces fradiae）、链霉菌（Streptomyces）sp. SCC-2136以及葡萄牙链霉菌（Streptomyces lusitanus）的乌达霉素（urdamycin）、Sch-47554以及grincamycin生物合成基因簇的同源基因的比对结果。为明确该基因簇的功能，研究人员将携带全部36个开放阅读框的表达黏粒载体（cosmid vector）转入变铅青链霉菌（Streptomyces lividans）TK23中。通过对培养提取物开展液相色谱-质谱联用（liquid chromatography–mass spectrometry，LC-MS）分析，证实该转化子可表达该生物合成基因并合成腐霉霉素。本研究成功鉴定并克隆了参与腐霉霉素生物合成的spr基因簇，并实现了腐霉霉素的异源表达生产。

搜集汇总

背景与挑战

背景概述

该数据集涉及从链霉菌TK08046中克隆和鉴定saprolmycin生物合成基因簇的研究。研究通过PCR和同源性分析，识别出包含36个开放阅读框的spr基因簇，该基因簇编码了angucycline生物合成相关基因，并成功在异源宿主中实现了saprolmycin的生产。数据集提供了相关实验数据和结果，支持抗生素生物合成机制的深入探索。