Schifrin Alexander, Khatri Yogan, Kirsch Philine, Thiel Verena, Schulz Stefan, Bernhardt Rita
Universität des Saarlandes, Institut für Biochemie, Campus B2.2, 66123 Saarbrücken, Germany.
Org Biomol Chem. 2016 Apr 7;14(13):3385-93. doi: 10.1039/c6ob00130k. Epub 2016 Mar 7.
The myxobacterium Sorangium cellulosum So ce56 is a prolific producer of volatile sesquiterpenes. The strain harbours one of the largest prokaryotic genomes (13.1 Mbp). However, it codes only for three type I terpene synthases (TSs; sce1440, sce6369, sce8552) and one type II TS (sce4636), responsible for the production of at least 17 sesquiterpenes. We report here the gene expression of TSs and biosynthesis of the TS products in E. coli. Comparison with the So ce56 volatiles allows the assignment of the terpenes to their synthesizing genes. Both, the geosmin synthase sce1440 and the previously examined (+)-eremophilene synthase sce8552 are highly specific. In contrast, Sce6369, the first characterized 10-epi-cubebol synthase, is responsible for the formation of most of the So ce56 sesquiterpenes, mainly cadalanes and cubebanes. In contrast, Sce4636 does not convert FPP. Having characterized the So ce56 TSs, we screened all the 27 sequenced myxobacterial species from the NCBI and JGI-IMG databases for parent genes to predict the sesquiterpenes produced by them.
粘细菌纤维堆囊菌So ce56是挥发性倍半萜的高产菌株。该菌株拥有最大的原核生物基因组之一(1310万碱基对)。然而,它仅编码三种I型萜类合酶(TSs;sce1440、sce6369、sce8552)和一种II型TS(sce4636),这些酶负责至少17种倍半萜的合成。我们在此报告TSs在大肠杆菌中的基因表达以及TS产物的生物合成。与So ce56挥发物的比较使我们能够将萜类化合物与其合成基因对应起来。土臭味素合酶sce1440和之前研究过的(+)-蛇床烯合酶sce8552都具有高度特异性。相比之下,首个被鉴定的10-表-荜澄茄醇合酶Sce6369负责So ce56中大多数倍半萜的形成,主要是杜松烷和荜澄茄烷。相反,Sce4636不能转化法尼基焦磷酸(FPP)。在对So ce56的TSs进行了表征之后,我们从NCBI和JGI-IMG数据库中筛选了所有27种已测序的粘细菌物种的亲本基因,以预测它们产生的倍半萜。