文献类型：期刊文献

英文题名：Dissecting and engineering of the TetR family regulator SACE_7301 for enhanced erythromycin production in Saccharopolyspora erythraea

作者：Wu, Hang[1];Chen, Meng[1];Mao, Yongrong[1];Li, Weiwei[1];Liu, Jingtao[1,4];Huang, Xunduan[1];Zhou, Ying[3];Ye, Bang-Ce[3];Zhang, Lixin[1,2];Weaver, David T.[1];Zhang, Buchang[1]

机构：[1]Anhui Univ, Inst Hlth Sci, Sch Life Sci, Hefei 230601, Peoples R China;[2]Chinese Acad Sci, Inst Microbiol, CAS Key Lab Pathogen Microbiol & Immunol, Beijing 100101, Peoples R China;[3]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[4]Beijing Inst Cell Biotechnol, Beijing 100043, Peoples R China

年份：2014

卷号：13

外文期刊名：MICROBIAL CELL FACTORIES

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000348546600001)】；

基金：This work was supported by the National Program on Key Basic Research Project (973 program, 2013CB734000), Open Funding Project of the State Key Laboratory of Bioreactor Engineering (2013), The National Natural Science Foundation of China (31300081, 30870069), The Natural Science Foundation of Anhui Province (1208085MC46), and The Initial Foundation of Doctoral Scientific Research in Anhui University (01001904). LZ is an Awardee for National Distinguished Young Scholar Program in China.

语种：英文

外文关键词：Saccharopolyspora erythraea; Erythromycin; SACE_7301; TetR family regulator; Gene overexpression; Metabolic engineering

摘要：Background: Saccharopolyspora erythraea was extensively utilized for the industrial-scale production of erythromycin A (Er-A), a macrolide antibiotic commonly used in human medicine. Yet, S. erythraea lacks regulatory genes in the erythromycin biosynthetic gene (ery) cluster, hampering efforts to enhance Er-A production via the engineering of regulatory genes. Results: By the chromosome gene inactivation technique based on homologous recombination with linearized DNA fragments, we have inactivated a number of candidate TetR family transcriptional regulators (TFRs) and identified one TFR (SACE_7301) positively controlling erythromycin biosynthesis in S. erythraea A226. qRT-PCR and EMSA analyses demonstrated that SACE_7301 activated the transcription of erythromycin biosynthetic gene eryAI and the resistance gene ermE by interacting with their promoter regions with low affinities, similar to BldD (SACE_2077) previously identified to regulate erythromycin biosynthesis and morphological differentiation. Therefore, we designed a strategy for overexpressing SACE_7301 with 1 to 3 extra copies under the control of PermE* in A226. Following up-regulated transcriptional expression of SACE_7301, eryAI and ermE, the SACE_7301-overexpressed strains all increased Er-A production over A226 proportional to the number of copies. Likewise, when SACE_7301 was overexpressed in an industrial S. erythraea WB strain, Er-A yields of the mutants WB/7301, WB/2x7301 and WB/3x7301 were respectively increased by 17%, 29% and 42% relative to that of WB. In a 5 L fermentor, Er-A accumulation increased to 4,230 mg/L with the highest-yield strain WB/3x7301, an approximately 27% production improvement over WB (3,322 mg/L). Conclusions: We have identified and characterized a TFR, SACE_7301, in S. erythraea that positively regulated erythromycin biosynthesis, and overexpression of SACE_7301 in wild-type and industrial S. erythraea strains enhanced Er-A yields. This study markedly improves our understanding of the unusual regulatory mechanism of erythromycin biosynthesis, and provides a novel strategy towards Er-A overproduction by engineering transcriptional regulators of S. erythraea.