中文摘要：

海洋放线菌是生理活性物质重要的产生菌,而海洋放线菌产生的卤化酶可催化生理活性物质的卤化,极大提高了其抑菌和抗癌活性。从大连海域分离出1株链霉菌Streptomyces sp.B-17,从其基因组DNA中扩增一524 bp的基因片段,经与pMD-19T载体连接,转化大肠埃希菌JM109感受态细胞,重组质粒经鉴定证明正向插入到pMD-19T载体。生物信息学分析表明该序列与Actinocorallia herbida DSM 44252的2个依赖FADH2卤化酶基因的同源性为88%,拟编码氨基酸与色氨酸卤化酶（CP001848）的相似性也达到74%,证明所克隆的基因片段为卤化酶基因片段,为后续的基因功能分析及表达奠定了基础。

英文摘要：

Marine actinomycetes（MA） are important sources of physiological active substances（PAS）,halogenase produced by the MA can catalyze the halogenization of the PAS,which greatly increased its antimicrobial and anticancer activities.A Streptomyces sp.B-17 strain was isolated from Dalian sea area,in this article a 524 bp gene fragment was amplified from its genomic DNA,after it was linked with pMD-19T vector and transferred into E.coli JM109 competence cell,the recombinant plasmid was identified and proved that it had been inserted in positive direction into pMD-19T vector.Bioinformatics analysis showed that the homology of the sequence of the cloned DNA fragment with two FADH2-dependent halogenase genes of Actinocorallia herbida DSM 44252 sequence was 88%,the similarity of the simulative encoded amino acid with tryptophan halogenase（CP001848） was also reached up to 74%,and it proved that the cloned gene fragment was halogenase gene fragment,and these had laid a foundation for the follow-up function analysis of the gene.