Maier Sarah, Heitzler Tanja, Asmus Katharina, Brötz Elke, Hardter Uwe, Hesselbach Katharina, Paululat Thomas, Bechthold Andreas
Institut für Pharmazeutische Biologie und Biotechnologie, Albert-Ludwigs Universität, Stefan-Meier-Strasse 19, 79104 Freiburg (Germany).
Organic Chemsitry II, Universität Siegen, Adolf-Reichwein-Strasse 2, 57068 Siegen (Germany).
Chembiochem. 2015 May 26;16(8):1175-82. doi: 10.1002/cbic.201500048. Epub 2015 Apr 23.
The biologically active compound mensacarcin is produced by Streptomyces bottropensis. The cosmid cos2 contains a large part of the mensacarcin biosynthesis gene cluster. Heterologous expression of this cosmid in Streptomyces albus J1074 led to the production of the intermediate didesmethylmensacarcin (DDMM). In order to gain more insights into the biosynthesis, gene inactivation experiments were carried out by λ-Red/ET-mediated recombination, and the deletion mutants were introduced into the host S. albus. In total, 23 genes were inactivated. Analysis of the metabolic profiles of the mutant strains showed the complete collapse of DDMM biosynthesis, but upon overexpression of the SARP regulatory gene msnR1 in each mutant new intermediates were detected. The compounds were isolated, and their structures were elucidated. Based on the results the specific functions of several enzymes were determined, and a pathway for mensacarcin biosynthesis is proposed.
生物活性化合物门杀癌素由波鸿链霉菌产生。黏粒cos2包含门杀癌素生物合成基因簇的很大一部分。该黏粒在白色链霉菌J1074中的异源表达导致了中间产物双去甲基门杀癌素（DDMM）的产生。为了更深入了解生物合成过程，通过λ-Red/ET介导的重组进行了基因失活实验，并将缺失突变体导入宿主白色链霉菌中。总共使23个基因失活。对突变菌株代谢谱的分析表明DDMM生物合成完全崩溃，但在每个突变体中过表达SARP调控基因msnR1后，检测到了新的中间产物。分离出这些化合物并阐明了它们的结构。基于这些结果确定了几种酶的具体功能，并提出了门杀癌素生物合成的途径。
