earticle

영어

Streptomyces natalensis produces natamycin, predominantly strong antifungal agent, inhibiting the growth of both yeasts and molds and preventing formation of aflatoxin in filamentous fungi. Due to the low toxicity of natamycin to mammalian cells compared to other antifungal compounds, it has found many applications in the treatment of various fungal diseases. Also, AfsR acts as a transcriptional factor in both the regulation of secondary metabolism and morphological differentiation in Streptomyces strains. In this study, PCR using the primers designed from the two highly conserved regions of the previously studied AfsR of Streptomyces strains gave 763- bp products. The sequence of this product had a high similarity to the expected region of an afsR gene. An intact 2,943 bp of afsR gene was cloned from S. natalensis by genomic Southern hybridization with PCR product as a probe, and then studied. To identify the function of the cloned afsR gene, it was inserted into pSET152ET to construct a high expression vector, and then was introduced into Streptomyces strains. The exconjugant including the high expression vector of afsR was constructed, and its phenotype was compared with the control strain. [This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology (2010-0008443)]