title: Design and production in Aspergillus niger of a chimeric protein associating a fungal feruloyl esterase and a clostridial dockerin domain.
abstract: A chimeric enzyme associating feruloyl esterase A (FAEA) from Aspergillus niger and dockerin from Clostridium thermocellum was produced in A. niger. A completely truncated form was produced when the dockerin domain was located downstream of the FAEA (FAEA-Doc), whereas no chimeric protein was produced when the bacterial dockerin domain was located upstream of the FAEA (Doc-FAEA). Northern blot analysis showed similar transcript levels for the two constructs, indicating a posttranscriptional bottleneck for Doc-FAEA production. The sequence encoding the first 514 amino acids from A. niger glucoamylase and a dibasic proteolytic processing site (kex-2) were fused upstream of the Doc-FAEA sequence. By using this fusion strategy, the esterase activity found in the extracellular medium was 20-fold-higher than that of the wild-type reference strain, and the production yield was estimated to be about 100 mg of chimeric protein/liter. Intracellular and extracellular production was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, dockerin-cohesin interaction assays, and Western blotting. Labeled cohesins detected an intact extracellular Doc-FAEA of about 43 kDa and a cleaved-off dockerin domain of about 8 kDa. In addition, an intracellular 120-kDa protein was recognized by using labeled cohesins and antibodies raised against FAEA. This protein corresponded to the unprocessed Doc-FAEA form fused to glucoamylase. In conclusion, these results indicated that translational fusion to glucoamylase improved the secretion efficiency of a chimeric Doc-FAEA protein and allowed production of the first functional fungal enzyme joined to a bacterial dockerin.
authors.affiliation: UMR 1163 INRA/Université de Provence de Biotechnologie des Champignons Filamenteux, IFR-IBAIM, Universités de Provence et de la Mediterranée, ESIL, 163 avenue de Luminy, Case Postale 925, 13288 Marseille cedex 09, France. anthony.levasseur@esil.univ-mrs.fr
authors.forename: Anthony
authors.initials: A
authors.lastname: Levasseur
authors.forename: Sandrine
authors.initials: S
authors.lastname: Pagès
authors.forename: Henri-Pierre
authors.initials: HP
authors.lastname: Fierobe
authors.forename: David
authors.initials: D
authors.lastname: Navarro
authors.forename: Peter
authors.initials: P
authors.lastname: Punt
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Belaïch
authors.forename: Marcel
authors.initials: M
authors.lastname: Asther
authors.forename: Eric
authors.initials: E
authors.lastname: Record
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D048013:Acetivibrio thermocellus / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins; D009687:Nuclear Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D014158:Transcription, Genetic; D014170:Transformation, Genetic; D000097722:Cohesins
chemical_list: D001426:Bacterial Proteins; D002265:Carboxylic Ester Hydrolases; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D000097722:Cohesins; C074074:cellulose binding protein A, Clostridium cellulovorans; C070196:feruloyl esterase