玫瑰黄链霉菌Men-myco-93-63负调控基因nsdAmgh的克隆及序列分析

nsdA (Negative regulator of Streptomyces differentiation)基因是天蓝色链霉菌中发现的与抗生素合成相关的负调控基因.根据天蓝色链霉菌 A3(2)的序列设计引物扩增玫瑰黄链霉菌 Men-myco-93-63 菌株中的该基因,经测序和序列分析表明,由保守序列引物nsdA-2R和nsdA-2L克隆到的Men-myco-93-63 菌株中的该基因 800 bp片段与已知nsdA基因核苷酸保守区域序列同源性达到99%,由全长序列扩增引物nsdA WZ-R和nsdA WZ-L克隆到的该基因包含一个完整的开放阅读框,共编码 369 个氨基酸,与变铅青链霉菌和天蓝色链霉菌A3(2)中的nsdA 基因的核苷酸序列同源性达到100%,氨基酸序列同源性达到99%.该全长基因命名为nsdA_(mgh),其在玫瑰黄链霉菌 Men-myco-93-63 中的发现为阻断该负调控基因以期获得抗生素高产工程菌株提供了重要依据.

Cloning and Sequence Analysis of nsdAmgh Gene in Streptomyces roseoflavus Men-myco-93-63

nsdA (Negative regulator of Streptomyces differentiation ) is globally negative regulator gene first found in Streptomyces coelicolor.In this study, nsdA gene of Streptomyces roseoflavus strains Men-myco-93-63 was amplified using the primer sequences designed from. Streptomyces coelicolor A3 (2) -After sequencing, Blastn, and Blastx,it showed that the cloned fragment from Streptomyces roseoflavus Men-myco-93-63 with the primer of nsdA-2R and nsdA-2L compairing with reported nsdA conservative nucleotide sequence homology on the region reached 99 % . The full-length gene sequence of Men-myco-93-63 nsdA gene amplification with primers of nsdA WZ-R and nsdA WZ-L had a complete open reading frame encoding 369 amino acids, with the Streptomyces lividans and Streptomyces coelicolor A3 (2) nsdA gene at nu-cleotide sequence 100% ,and amino acid sequence homology up to 99% .The full-length nsdA gene of Streptomyces rose-oflavus Men-myco-93-63 was named nsdA_(mgh), which will promote the obtaintion of high-yielding antibiotic strains of Streptomyces roseoflavus Men-myco-93-63 through interrupting the negative regulator.