ste7与ste15双基因敲除对依博素生物合成的影响

摘要：【目的】研究ste7和ste15基因双敲除对依博素生物合成的影响。【方法】通过基因同源重组双交换，对ste15基因缺失突变株Streptomyces sp. 139 (ste15 -)再进行ste7基因的敲除，经Southern杂交验证，获得了ste7和ste15双基因缺失变株Streptomyces sp. 139 (ste7 - ste15 -)。对该突变株进行了基因互补。气相色谱分析ste7和ste15双基因缺失突变株及互补株产生的胞外多糖单糖组分，排阻色谱测定衍生物的重均分子量，ELISA法

The effects of genes ste7-ste15 double disruption in Ebosin biosynthesis

Abstract: Objective] To study the effects of genes ste7-ste15 double disruption in biosynthesis of Ebosin. Methods] The ste7 gene was disrupted with a double crossover via homologous recombination in the mutant strain Streptomyces sp. The 139 (ste15 -) and the mutant strain Streptomyces sp.139 (ste7 -ste15 -) were identified by Southern blot. Gene complementation of the knock-out mutant was done. Monosaccharide composition of the exopolysaccharides EPS15-7m, EPS15-7c producing by Streptomyces sp.139 (ste7 -ste15 -) and Streptomyces sp.139 (pKC7-15c) separately were analyzed by Gas Chromatography, while their Mw and the antagonist activity for IL-1R were determined comparing with Ebosin. Results] The mutant strain Streptomyces sp.139 (ste7 -ste15 -) and complementary strain Streptomyces sp.139 (pKC7-15c) were constructed respectively. The analysis results showed that both of fucose and glucose decreased remarkably in EPS15-7m and its Mw and the antagonist activity for IL-1R were much lower than Ebosin. The composition of fucose and glucose were recovered notablely in EPS15-7c compared with EPS15-7m. Conclusion] The genes ste7 and ste15 played essential roles in the synthesis process of sugar repeating unit during biosynthesis of Ebosin. The activities of Ebosin new derivative produced by the mutant will be studied further.