LAUSR

Lincomycin produced by Streptomyces lincolnensis is a critical antibacterial antibiotic in the clinical. To further understand the regulatory mechanism of lincomycin biosynthesis, we identified an alternative σ factor, σLsl, in Streptomyces lincolnensis NRRL 2936. Deletion of sigLsl resulted in an increase in cell growth but a decrease in lincomycin production. σLsl boosted lincomycin biosynthesis by directly stimulating the transcription of four genes (lmbD, lmbV, lmrC, and lmbU) within the lincomycin biosynthetic lmb gene cluster. Besides, σLsl participated in lincomycin biosynthesis by directly stimulating the transcription of mshC, a gene responsible for MSH synthesis. In conclusion, our findings demonstrated that σLsl plays a direct regulatory role in lincomycin biosynthesis. This study extends the understanding of molecular mechanisms of lincomycin biosynthetic regulation.