Identification of a cluster-situated activator of oxytetracycline biosynthesis and manipulation of its expression for improved oxytetracycline production in Streptomyces rimosus

• DOI: 10.1186/s12934-015-0231-7
• Publication Date: 2015-04-02T17:06:04Z
• Authors: Shouliang Yin; Weishan Wang; Xuefeng Wang; Yaxin Zhu; Xiaole Jia; Shanshan Li; Fang Yuan; Yuxiu Zhang; Keqian Yang
• Keywords: Gene cluster; Transcription; Heterologous expression

Oxytetracycline (OTC) is a broad-spectrum antibiotic commercially produced by Streptomyces rimosus. Despite its importance, little known about the regulation of OTC biosynthesis, which hampered any effort to improve production via engineering regulatory genes.A gene encoding protein (SARP) was discovered immediately adjacent otrB oxy cluster in S. rimosus and designated otcR. Deletion complementation otcR abolished or restored production, respectively, indicating that encodes an essential activator biosynthesis. Then, predicted consensus SARP-binding sequences were extracted from promoter regions cluster. Transcriptional analysis heterologous GFP reporter system demonstrated OtcR directly activated transcription five promoters E. coli, further mutational sequence oxyI proved interacted with repeats. Therefore, chosen as target, significantly increased overexpression tandem copies each under control strong SF14 promoter.A SARP activator, OtcR, identified rimosus; it shown activate Overexpression at appropriate level dramatically 6.49 times compared parental strain, thus demonstrating great potential manipulating yield production.