文献类型：期刊文献

英文题名：Protein expression analysis of a high-demeclocycline producing strain of Streptomyces aureofaciens and the roles of CtcH and CtcJ in demeclocycline biosynthesis

作者：Li, Hong[1]; Ye, Ruifang[1]; Lin, Guizhen[1]; Zhu, Deyu[2]; Mao, Quangui[2]

机构：[1] The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] Topfond Pharmaceutical Co., Ltd, Henan, China

年份：2016

卷号：3

期号：1

外文期刊名：Bioresources and Bioprocessing

收录：EI(收录号：20224513081441)

语种：英文

外文关键词：Bacteria - Biochemistry - Electrophoresis - Encoding (symbols) - Enzymes - Metabolism

摘要：Background: Streptomyces aureofaciens strain A6-9, obtained with traditional mutagenesis, produces elevated levels of 6-DCT. The increased formation of 6-DCT may be attributable to the changes in the expression of some proteins in the 6-DCT biosynthetic pathway. For this reason, we explored the differences in protein expression between A6-9 and wild-type (WT) strains of Streptomyces aureofaciens, and based on the differences (CtcH and CtcJ were overexpressed in A6-9), investigated the roles of CtcH and CtcJ in biosynthesis. Results: Two-dimensional gel electrophoresis and a Mascot search indicated that some enzymes (including CtcH and CtcJ) involved in the primary and secondary metabolism were more strongly expressed in the high-6-DCT-yielding strain A6-9 than in the WT strain DT1. To examine the roles of CtcH and CtcJ in 6-DCT biosynthesis, ctcH-deleted, ctcJ-deleted, ctcH-overexpressing, and ctcJ-overexpressing mutants and a mutant overexpressing both ctcH and ctcJ were constructed. Compared with WT, 6-DCT production was 50 and 37% higher in the ctcH-overexpressing and ctcJ-overexpressing strains, respectively, and increased by 60 % in the ctcH–ctcJ-overexpressing strain. The ctcH-deleted and ctcJ-deleted strains produced almost no 6-DCT. Analysis of the metabolic flux distribution indicated that ctcH encodes a hydroxyacyl-CoA dehydrogenase and ctcJ encodes a monooxygenase that are essential for 6-DCT biosynthesis. Conclusion: Protein expression differs between high-6-DCT-yielding and WT strains, and the enzymes increased in the high-6-DCT-yielding strain explain the increased 6-DCT production. ctcH encodes a hydroxyacyl-CoA dehydrogenase and ctcJ encodes a monooxygenase that are essential for 6-DCT biosynthesis. ? 2016, The Author(s).