High-level expression of whiG—A key gene for Streptomyces differentiation in Escherichia coli

摘要

Six nucleotides located in the region of translation start site of whiG were changed, whiG was amplified by PCR technique. Reformed sequences were determined. This gene was directly subcloned into expression vector pET11c containing strong T7 promoter, and the recombinant plasmid was introduced into E. coli BL21(DE3), which could be induced by IPTG to produce T7 RNA polymerase. The SDS-PAGE result showed that whiG highly expressed in E. coli BL21(DE3), and the yield of whiG product was about 20% of insoluble proteins in cell. whiG product (sigma~(whiG)) was further identified by Western blot hybridization after making its antibody whiG gene was subcloned into Streptomyces plasmid pl,16021, and then it was introduced into sporulation deficient mutantC71 from Streptomyces coelicolor. The result showed that C71 could restore sponilation and sigma~(whiG) has biological functions.