m4C DNA methylation regulates biosynthesis of daptomycin in Streptomyces roseosporus L30

Synth Syst Biotechnol. 2022 Jun 17;7(4):1013-1023. doi: 10.1016/j.synbio.2022.06.001. eCollection 2022 Dec.

Abstract

Despite numerous studies on transcriptional level regulation by single genes in drug producing Actinomyces, the global regulation based on epigenetic modification is not well explored. N4-methylcytosine (m4C), an abundant epigenetic marker in Actinomycetes' genome, but its regulatory mechanism remains unclear. In this study, we identify a m4C methyltransferase (SroLm3) in Streptomyces roseosporus L30 and multi-omics studies were performed and revealed SroLm3 as a global regulator of secondary metabolism. Notably, three BGCs in ΔsroLm3 strain exhibited decreased expression compared to wild type. In-frame deletion of sroLm3 in S.roseosporus L30 further revealed its role in enhancing daptomycin production. In summary, we characterized a m4C methyltransferase, revealed the function of m4C in secondary metabolism regulation and biosynthesis of red pigment, and mapped a series of novel regulators for daptomycin biosynthesis dominated by m4C methylation. Our research further indicated that m4C DNA methylation may contribute to a metabolic switch from primary to secondary metabolism in Actinomyces.

Keywords: DNA methyltransferase; Daptomycin; N4-methylcytosine; Secondary metabolism; Transcriptional regulator.