从实验室保藏的菌株中筛选出一株产DDE转座酶的菌，经形态及生理生化、16S rDNA及建树分析比对，该菌株属链霉菌属灰褐类群，暂将其命名为Streptomyces labedae sp. X1。从Streptomyces labedae sp. X1基因组DNA扩增一401 bp的DDE转座酶基因，通过Blast和ISfinder数据库进行序列比对，结果显示其与ISAzo13家族转座酶的基因有88%的相似度。通过对其进行生物信息学分析，发现该基因可编码133个氨基酸，且该DDE转座酶的保守的氨基酸三联体分别位于Asp43、Asp49、Glu91上，理化性质结果显示编码产物为稳定的亲水蛋白；二级结构以α-螺旋和无规则卷曲为主，不存在信号肽和跨膜结构域，为非分泌蛋白；有14个磷酸化位点且仅有一个糖基化位点；高级结构以α-螺旋为主；通过SDS-聚丙烯酰胺凝胶电泳，结果显示在27 ku处出现条带。该研究结果为研究链霉菌DDE转座酶基因的表达机制提供了重要信息，对以后鉴定DDE转座酶活性以及它的结构和功能奠定基础。

In this paper, a DDE transposase-producing strain was selected from the strains preserved in the laboratory and indentified as Streptomyces labedae sp. X1 by morphology, physi-biochemistry and 16S rDNA. One 401 bp DDE transposase gene was amplified from the Streptomyces labedae sp. X1 genomic DNA, Blast and ISfinder results showed that it had 88% similarity with ISAzo13 family transposase genes. Bioinformatics analysis showed that the gene encoded 133 amino acids with stable hydrophilic structure, and the conserved amino acid triplet of Asp43, Asp49, Glu91 were found in the amplified DDE transposase; Based on the results of its α-spiral and irregular crimp, absence of signal peptides and transmembrane domains, it was a non-secreting protein with 14 phosphorylation and only one glycosylation site; and α-helix was the main composition in its advanced structure; SDS-polyacrylamide gelelectrophoresis showed that the molecular weight of the proposed protein was 27 ku. The results provide important information for the study of the expression mechanism of Streptomyces DDE transposase gene, and lay a foundation for the identification of DDE transposase activity, its structure and function in the future.

辽宁省自然科学基金项目（20180550858）