In Vivo Analysis of fadB Homologous Enzymes Involved in Biosynthesis of Polyhydroxyalkanoates in Recombinant Escherichia coli

재조합 대장균에서 fadB 유사효소의 Polyhydroxyalkanoates 합성에 미치는 역할의 규명

  • 최종일 (한국과학기술원 생명화학공학과, 생물공정연구센터 및 대사공학 국가지정연구실) ;
  • 박시재 (한국과학기술원 생명화학공학과, 생물공정연구센터 및 대사공학 국가지정연구실) ;
  • 이상엽 (한국과학기술원 바이오시스템학과)
  • Published : 2004.08.01

Abstract

In vivo characterization of FadB homologous enzymes including PaaG, YdbU and YgfG for medium-chain-length (MCL) polyhydroxyalkanoate (PHA) biosynthesis was carried out in fadB mutant Escherichia coli. Previously, it was reported that amplification of FadB homologous enzymes such as PaaG and YdbU in fadB mutant E. coli resulted in enhanced biosynthesis of MCL-PHA by greater than two fold compared with control strain. In this study, we constructed paaG fadB double mutant E. coli WB114 and ydbU fadB double mutant E. coli WB115 to investigate the roles of PaaG and YdbU in biosynthesis of MCL-PHA. Inactivation of paaG and ydbU genes in fadB mutant E. coli harboring Pseudomonas sp. 61-3 phaC2 gene reduced the MCL-PHA production to 0.16 and 0.16 PHA g/L, respectively from 2 g/L of sodium decanoate, which are much lower than 0.43 PHA g/L obtained with fadB mutant E. coli WB101 harboring the phaC2 gene. Also, we identified new FadB homologous enzyme YgfG, and examined its roles by overexpression of ygfG and construction of ygfG fadB double mutant E. coli WB113.

재조합 E. coli를 이용한 MCL-PHA의 생산에서 fatty acid pathway로부터 PHA 생합성 전구체 물질들이 만들어진다는 사실과 함께 이에 관여하는 enzymes이 밝혀지고 있다. 본 논문에서는 protein homology search로부터 탐색된 paaG와 ydbU genes의 PHA 생합성에서의 역할을 확인하기 위하여 paaG와 ydbU gene이 각각 knock-out된 mutant E. coli strains 를 제작하였다. 제작된 mutant E. coli들은 모균주들보다 낮은 PHA 농도와 함량을 가졌으며, 이러한 결과들로부터 paaG와 ydbU는 fatty acid pathway에서 PHA synthesis의 전구체 물질들을 공급한다는 사실을 확인하였다. 또한, 새로운 FadB homologous enzyme YgfG를 탐색하였으며, ygfG gene이 overexpression된 균주와 ygfG mutant를 제작하여 PHA 합성을 실험한 결과 ygfG도 paaG와 ydbU와 유사한 역할을 한다는 사실을 밝혔다. 이러한 연구결과들은 E. coli에서의 MCL-PHA 단량체들의 합성 경로를 확인하여 효과적인 PHA 생산 균주를 제작할 수 있게 할 것이다.

Keywords

References

  1. Biotechnol. Bioeng. v.49 Bacterial polyhydroxyalkanoates Lee, S. Y. https://doi.org/10.1002/(SICI)1097-0290(19960105)49:1<1::AID-BIT1>3.3.CO;2-1
  2. Microbiol. Mol. Biol. Rev. v.63 Metabolic engineering of poly(3-hydroxyalkanoates): from DNA to plastic Madison, L. L.;G. W. Huisman
  3. FEMS Microbiol. Lett. v.128 Diversity of bacterial polyhydroxyalkanoic acid Steinbuchel, A.;H. E. Valentin https://doi.org/10.1111/j.1574-6968.1995.tb07528.x
  4. Biotechnol. Bioeng. v.62 Efficient and economical recovery of poly(3-hydroxybutyate) from recombinant Escherichia coli by simple digestion with chemicals Choi, J.;S. Y. Lee https://doi.org/10.1002/(SICI)1097-0290(19990305)62:5<546::AID-BIT6>3.0.CO;2-0
  5. FEMS Microbiol. Lett. v.157 Synthesis of poly(3-hydroxyalkanoates) in Escherichia coli expressing the PHA synthase gene phaC2 from Pseudomonas aeruginosa: comparison of PhaC1 and PhaC2 Qi, Q.;B. H. A. Rehm;A. Steibuchel https://doi.org/10.1111/j.1574-6968.1997.tb12767.x
  6. J. Bacteriol. v.185 Identification and characterization of a new enoyl coenzyme A hydratase involved in biosynthesis of medium-chain-length polyhydroxyalkanoates in recombinant E. coli Park, S. J.;S. Y. Lee https://doi.org/10.1128/JB.185.18.5391-5397.2003
  7. J. Bacteriol. v.182 FabG, an NADPH-dependent 3-ketoacyl reductase of Pseudomonas aeruginosa, provides precursors for medium-chain-length poly-3-hydroxyalkanoate biosynthesis in Escherichia coli Ren, Q.;N. Sierro;B. Witholt;B. Kessler https://doi.org/10.1128/JB.182.10.2978-2981.2000
  8. FEMS Microbiol. Lett. v.176 Co-expression of 3-ketoacyl-ACP reductase and polyhydroxyalkanoate synthase genes induces PHA production in Escherihia coli HB101 strain Taguchi, K.;Y. Aoyagi;H. Matsusaki;T. Fukui;Y. Doi https://doi.org/10.1111/j.1574-6968.1999.tb13660.x
  9. Int. J. Biol. Macromol. v.31 Molecular characterization and properties of (R)-specific enoyl-CoA hydratases from Pseudomonas aeruginosa: metabolic tools for synthesis of polyhydroxyalkanoates via fatty acid ${\beta}$-oxidation Tsuge, T.;K. Taguchi;S. Taguchi;Y. Doi https://doi.org/10.1016/S0141-8130(02)00082-X
  10. J. Bacteriol. v.184 YfcX enables medium-chain-length poly(3-hydroxyalkanoate) formation from fatty acids in recombinant Escherichia coli fadB strains Snell, K. D.;F. Feng;L. Zhong;D. Martin;L. L. Madison https://doi.org/10.1128/JB.184.20.5696-5705.2002
  11. Biotechnol. Bioeng. New fadB homologous enzymes and their use in enhanced biosynthesis of medium-chain-length Polyhydroxyalkanoates in fadB mutant Escherichia coli Park, S. J.;S. Y. Lee
  12. Enzyme Microb. Technol. v.33 Enrichment of specific monomer in medium-chain-length poly(3-hydroxyalkanoates) by amplification of fadD and fadE genes in recombinant Escherichia coli Park, S. J.;J. P. Park;S. Y. Lee;Y. Doi https://doi.org/10.1016/S0141-0229(03)00093-0
  13. Science v.277 The complete genome sequence of Escherichia coli K-12 Blattner, F. R.;G. Plunkett;C. A. Bloch;N. T. Perna;V. Burland;M. Riley;J. Collado-Vides;J. D. Glasner;K. Rode;G. F. Mayhew;J. Gregor;N. W. Davis;H. A. Kirkpatrick;M. A. Goeden;D. J. Rose;B. Mau;Y. Shao https://doi.org/10.1126/science.277.5331.1453
  14. Eur. J. Appl. Microbiol. Biotechnol. v.6 A rapid gas chromatographic method for the determination of poly-(hydroxybutyric acid in microbial biomass Braunegg, G.;B. Sonnleitner;R. M. Lafferty https://doi.org/10.1007/BF00500854
  15. Biotechnol. Bioprocess Eng. v.7 Pilot scale production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by fed-batch culture of recombinant Escherichia coli Choi, J.;S. Y. Lee;K. Shin;W. G. Lee;S. J. Park;H. N. Chang;Y. K. Chang https://doi.org/10.1007/BF02933524
  16. J. Bacteriol. v.180 Cloning and molecular analysis of the Poly(3-hydroxybutyrate) and Poly(3-hydroxybutyrate-co-3-hydroxyalkanoate) biosynthesis genes in Pseudomonas sp. strain 61-3 Matsusaki, H.;S. Manji;K. Taguchi;M. Kato;T. Fukui;Y. Doi
  17. Appl. Environ. Microbiol. v.68 Metabolic Engineering of a Novel Propionate-Independent Pathway for the Production of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) in Recombinant Salmonella enterica Serovar Typhimurim Aldor, I. S.;S. Kim;K. L. Jones Prather;J. D. Keasling https://doi.org/10.1128/AEM.68.8.3848-3854.2002