title: Production of functionally active Penicillium chrysogenum isopenicillin N synthase in the yeast Hansenula polymorpha.
abstract: BACKGROUND
  beta-Lactams like penicillin and cephalosporin are among the oldest known antibiotics used against bacterial infections. Industrially, penicillin is produced by the filamentous fungus Penicillium chrysogenum. Our goal is to introduce the entire penicillin biosynthesis pathway into the methylotrophic yeast Hansenula polymorpha. Yeast species have the advantage of being versatile, easy to handle and cultivate, and possess superior fermentation properties relative to filamentous fungi. One of the fundamental challenges is to produce functionally active enzyme in H. polymorpha.
  
  
  RESULTS
  The P. chrysogenum pcbC gene encoding isopenicillin N synthase (IPNS) was successfully expressed in H. polymorpha, but the protein produced was unstable and inactive when the host was grown at its optimal growth temperature (37 degrees C). Heterologously produced IPNS protein levels were enhanced when the cultivation temperature was lowered to either 25 degrees C or 30 degrees C. Furthermore, IPNS produced at these lower cultivation temperatures was functionally active. Localization experiments demonstrated that, like in P. chrysogenum, in H. polymorpha IPNS is located in the cytosol.
  
  
  CONCLUSIONS
  In P. chrysogenum, the enzymes involved in penicillin production are compartmentalized in the cytosol and in microbodies. In this study, we focus on the cytosolic enzyme IPNS. Our data show that high amounts of functionally active IPNS enzyme can be produced in the heterologous host during cultivation at 25 degrees C, the optimal growth temperature for P. chrysogenum. This is a new step forward in the metabolic reprogramming of H. polymorpha to produce penicillin.
authors: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands. L.Gidijala@rug.nl
authors: Loknath
authors: L
authors: Gidijala
authors: Roel A L
authors: RA
authors: Bovenberg
authors: Paul
authors: P
authors: Klaassen
authors: Ida J
authors: IJ
authors: van der Klei
authors: Marten
authors: M
authors: Veenhuis
authors: Jan A K W
authors: JA
authors: Kiel
mesh_terms: D004789:Enzyme Activation; D004795:Enzyme Stability; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010408:Penicillium chrysogenum / Q000235:genetics / Q000378:metabolism*; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D010088:Oxidoreductases; C038370:isopenicillin N synthetase