Structural and functional characterization of three polyketide synthase gene clusters in Bacillus amyloliquefaciens FZB 42
Structural and functional characterization of three polyketide synthase gene clusters in Bacillus amyloliquefaciens FZB 42
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DOI：
10.1128/jb.00052-06
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发表时间：
2006-06-01
影响因子：
3.2
通讯作者：
Borriss, Rainer
中科院分区：
文献类型：
--
作者：
Chen, Xiao-Hua;Vater, Joachim;Borriss, Rainer
尽管细菌聚酮具有相当大的生物医学价值，但作为生物活性天然产物最丰富的细菌来源之一，芽孢杆菌聚酮生物合成的分子生物学仍未得到很大程度的探索。在这里，我们首次将完整的聚酮合成酶(PKS)基因簇归属于芽孢杆菌抗生素。在淀粉解聚芽孢杆菌FZB-42中鉴定出三个反式酰基转移酶类型的巨型模块化PKS系统。其中pks1是在已测序的模式菌株枯草杆菌168中具有未知功能的pksX操纵子的同源基因，而pks2和pks3簇是新的基因簇。盒式诱变结合基质辅助激光解吸电离飞行时间质谱仪和高效电喷雾电离质谱仪等先进的质谱学技术，发现pks 1(Bae)和pks 3(Dif)基因簇分别编码多烯类抗生素杆菌烯和艰难定或氧化艰难定的生物合成。此外，枯草杆菌168衍生物JH642的转化子OKB105(PHEA SFP(0))也能产生细菌烯，这表明pksX基因簇指导了该聚酮的合成。
Although bacterial polyketides are of considerable biomedical interest, the molecular biology of polyketide biosynthesis in Bacillus spp., one of the richest bacterial sources of bioactive natural products, remains largely unexplored. Here we assign for the first time complete polyketide synthase (PKS) gene clusters to Bacillus antibiotics. Three giant modular PKS systems of the trans-acyltransferase type were identified in Bacillus amyloliquefaciens FZB 42. One of them, pks1, is an ortholog of the pksX operon with a previously unknown function in the sequenced model strain Bacillus subtilis 168, while the pks2 and pks3 clusters are novel gene clusters. Cassette mutagenesis combined with advanced mass spectrometric techniques such as matrix-assisted laser desorption ionization-time of flight mass spectrometry and liquid chromatography-electrospray ionization mass spectrometry revealed that the pks1 (bae) and pks3 (dif) gene clusters encode the biosynthesis of the polyene antibiotics bacillaene and difficidin or oxydifficidin, respectively. In addition, B. subtilis OKB105 (pheA sfp(0)), a transformant of the B. subtilis 168 derivative JH642, was shown to produce bacillaene, demonstrating that the pksX gene cluster directs the synthesis of that polyketide.