title: Regulating malonyl-CoA metabolism via synthetic antisense RNAs for enhanced biosynthesis of natural products.
abstract: Malonyl-CoA is the building block for fatty acid biosynthesis and also a precursor to various pharmaceutically and industrially valuable molecules, such as polyketides and biopolymers. However, intracellular malonyl-CoA is usually maintained at low levels, which poses great challenges to efficient microbial production of malonyl-CoA derived molecules. Inactivation of the malonyl-CoA consumption pathway to increase its intracellular availability is not applicable, since it is usually lethal to microorganisms. In this work, we employ synthetic antisense RNAs (asRNAs) to conditionally down-regulate fatty acid biosynthesis and achieve malonyl-CoA enrichment in Escherichia coli. The optimized asRNA constructs with a loop-stem structure exhibit high interference efficiency up to 80%, leading to a 4.5-fold increase in intracellular malonyl-CoA concentration when fabD gene expression is inhibited. Strikingly, this strategy allows the improved production of natural products 4-hydroxycoumarin, resveratrol, and naringenin by 2.53-, 1.70-, and 1.53-fold in E. coli, respectively. In addition, down-regulation of other fab genes including fabH, fabB, and fabF also leads to remarkable increases in 4-hydroxycoumarin production. This study demonstrates a novel strategy to enhance intracellular malonyl-CoA and indicates the effectiveness of asRNA as a powerful tool for use in metabolic engineering.
authors: College of Engineering, University of Georgia, Athens, GA 30602, USA.
authors: Yaping
authors: Y
authors: Yang
authors: College of Engineering, University of Georgia, Athens, GA 30602, USA.
authors: Yuheng
authors: Y
authors: Lin
authors: Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors: Lingyun
authors: L
authors: Li
authors: Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors: Robert J
authors: RJ
authors: Linhardt
authors: BioChemical Engineering Program, College of Engineering, University of Georgia, Athens, GA 30602, USA. Electronic address: yajunyan@uga.edu.
authors: Yajun
authors: Y
authors: Yan
mesh_terms: D051080:Acyl-Carrier Protein S-Malonyltransferase / Q000096:biosynthesis*; D029968:Escherichia coli Proteins / Q000096:biosynthesis*; D054889:Fatty Acid Synthase, Type II / Q000096:biosynthesis; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008316:Malonyl Coenzyme A / Q000235:genetics / Q000378:metabolism; D016372:RNA, Antisense / Q000096:biosynthesis / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D016372:RNA, Antisense; D008316:Malonyl Coenzyme A; D051080:Acyl-Carrier Protein S-Malonyltransferase; C494968:fabD protein, E coli; D054889:Fatty Acid Synthase, Type II
keywords: 4-hydroxycoumarin; Antisense RNA; Fatty acid biosynthesis; Malonyl-CoA; Naringenin; Resveratrol