title: Engineering of an Lrp family regulator SACE_Lrp improves erythromycin production in Saccharopolyspora erythraea.
abstract: Leucine-responsive regulatory proteins (Lrps) are a group of transcriptional regulators that regulate diverse cellular processes in bacteria and archaea. However, the regulatory role of Lrps in antibiotic biosynthesis remains poorly understood. In this study, we show that SACE_5388, an Lrp family regulator named as SACE_Lrp, is an efficient regulator for transporting and catabolizing branched-chain amino acids (BCAAs), playing an important role in regulating erythromycin production in Saccharopolyspora erythraea. SACE_Lrp directly controlled the expression of the divergently transcribed SACE_5387-5386 operon putatively encoding a BCAA ABC transporter by interacting with the intergenic region between SACE_Lrp and SACE_5387 (SACE_Lrp-5387-int), and indirectly controlled the expression of ilvE putatively encoding an aminotransferase catabolizing BCAAs. BCAA catabolism is one source of the precursors for erythromycin biosynthesis. Lysine and arginine promoted the dissociation of SACE_Lrp from SACE_Lrp -5387-int, whereas histidine increased their binding. Gene disruption of SACE_Lrp (ΔSACE_Lrp) in S. erythraea A226 resulted in a 25% increase in erythromycin production, while overexpression of SACE_5387-5386 in A226 enhanced erythromycin production by 36%. Deletion of SACE_Lrp (WBΔSACE_Lrp) in the industrial strain S. erythraea WB enhanced erythromycin production by 19%, and overexpression of SACE_5387-5386 in WBΔSACE_Lrp (WBΔSACE_Lrp/5387-5386) increased erythromycin production by 41% compared to WB. Additionally, supplement of 10mM valine to WBΔSACE_Lrp/5387-5386 culture further increased total erythromycin production up to 48%. In a 5-L fermenter, the erythromycin accumulation in the engineered strain WBΔSACE_Lrp/5387-5386 with 10mM extra valine in the industrial culture media reached 5001mg/L, a 41% increase over 3503mg/L of WB. These insights into the molecular regulation of antibiotic biosynthesis by SACE_Lrp in S. erythraea are instrumental in increasing industrial production of secondary metabolites.
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Jing
authors: J
authors: Liu
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Yunfu
authors: Y
authors: Chen
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Weiwei
authors: W
authors: Wang
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Min
authors: M
authors: Ren
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Panpan
authors: P
authors: Wu
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Yansheng
authors: Y
authors: Wang
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China.
authors: Changrun
authors: C
authors: Li
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China; CAS Key Laboratory of Pathogenic Microbiology & Immunology, Drug Discovery Center for Tuberculosis, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors: Lixin
authors: L
authors: Zhang
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China. Electronic address: wuh2007@gmail.com.
authors: Hang
authors: H
authors: Wu
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China. Electronic address: David.weaver.t@gmail.com.
authors: David T
authors: DT
authors: Weaver
authors: Institute of Health Sciences, School of Chemistry and Chemical Engineering, School of Life Sciences, Anhui University, Hefei 230601, China. Electronic address: zhbc@ahu.edu.cn.
authors: Buchang
authors: B
authors: Zhang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D053898:Biosynthetic Pathways / Q000235:genetics*; D004917:Erythromycin / Q000096:biosynthesis* / Q000302:isolation & purification; D024861:Genetic Enhancement / Q000379:methods*; D051756:Leucine-Responsive Regulatory Protein / Q000235:genetics*; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics; D016930:Saccharopolyspora / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D051756:Leucine-Responsive Regulatory Protein; D004917:Erythromycin
keywords: Branched-chain amino acid; Engineering; Erythromycin; Leucine-responsive regulatory protein; Saccharopolyspora erythraea