圈卷产色链霉菌分化相关基因——saw1的结构和功能

用双脱氧链终止法进行了分化基因——saw1的双链测序.结果表明在1500bp的DNA片段中有一个完整的开读框架(ORF),其编码区是在419bp至1252bp处.其产物与已知的天蓝色链霉菌whiG的氨基酸序列有89%的同源性.当把1500bp的saw1DNA片段插入到链霉菌表达质粒载体pIJ702后,构建的重组质粒转化天蓝色链霉菌孢子形成缺陷突变株C71,可使C71形成孢子和灰色色素.用基因破坏的策略进一步研究了该基因的生物学功能,结果表明saw1在圈卷产色链霉菌气生菌丝到孢子形成的发育转变中有重要作用,是分化中控制孢子发育起始的一个重要基因.

STRUCTURE AND FUNCTION OF SAW1-A GENE RELATED TODIFFERENTIATION OF STREPTOMYCES ANSOCHROMOGENES

The DNA sequence of double strands of saw1 gene was determined by the method of chaintermination inhibitors. The result indicated that the 1500 bp of DNA fragment displayed a complete open reading frame (ORF), the encoding regions were located in 419 to 1252 bp positions, saw1 product has 89% identity to amino acids of sigma whiG of Streptomyces coelicolor. When recombinant plasmid containing a 1500 bp saw1 DNA fragment insert in plasmid pIJ702 was introduced into Streptomyces coelicolor C71, the sporulation deficient mutant C71 could form spore and produce grey pigment. The gene function was studied by using the method of gene disruption and the result showed that the saw1 played an important role in developmental changes from aerial hypha to spore formation of Streptomyces ansochromogenes.