title: Engineering the intracellular metabolism of Escherichia coli to produce gamma-aminobutyric acid by co-localization of GABA shunt enzymes.
abstract: OBJECTIVE
  To direct the carbon flux from Krebs cycle into the gamma-aminobutyric acid (GABA) shunt pathway for the production of GABA by protein scaffold introduction in Escherichia coli.
  
  
  RESULTS
  Escherichia coli was engineered to produce GABA from glucose by the co-localization of enzymes succinate semialdehyde dehydrogenase (GadD), GABA aminotransferase (PuuE) and GABA transporter (GadC) by protein scaffold. 0.7 g GABA l(-1) was produced from 10 g glucose l(-1) while no GABA was produced in wild type E. coli. pH 6 and 30 °C were optimum for GABA production, and GABA concentration increased to 1.12 g GABA l(-1) when 20 g glucose l(-1) was used. When competing metabolic networks were inactivated, GABA increased by 24 % (0.87 g GABA l(-1)).
  
  
  CONCLUSIONS
  The novel GABA production system was constructed by co-localization of GABA shunt enzymes.
authors.affiliation: Department of Chemical Engineering, University of Ulsan, 93 Daehakro, Nam-gu, Ulsan, 680-749, Republic of Korea.
authors.forename: Van Dung
authors.initials: VD
authors.lastname: Pham
authors.affiliation: Department of Chemical Engineering, University of Ulsan, 93 Daehakro, Nam-gu, Ulsan, 680-749, Republic of Korea.
authors.forename: Sivachandiran
authors.initials: S
authors.lastname: Somasundaram
authors.affiliation: Department of Biotechnology&Bioengineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 500-757, Republic of Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Environmental Engineering and Energy, Myongji University, San 38-2, Nam-dong, Cheoin-gu, Yongin-si, Gyeonggido, 449-728, Republic of Korea.
authors.forename: Si Jae
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Chemical Engineering, University of Ulsan, 93 Daehakro, Nam-gu, Ulsan, 680-749, Republic of Korea. shhong@ulsan.ac.kr.
authors.forename: Soon Ho
authors.initials: SH
authors.lastname: Hong
mesh_terms: D000612:4-Aminobutyrate Transaminase / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D050644:Succinate-Semialdehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; C491226:GadC protein, E coli; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D005680:gamma-Aminobutyric Acid; D050644:Succinate-Semialdehyde Dehydrogenase; D000612:4-Aminobutyrate Transaminase; D005947:Glucose
keywords: Co-localization; Escherichia coli; Gamma-Scaffold system; Gamma-aminobutyric acid; Gamma-aminobutyric acid shunt