title: Characterizing MttA as a mitochondrial cis-aconitic acid transporter by metabolic engineering.
abstract: The mitochondrial carrier protein MttA is involved in the biosynthesis of itaconic acid in Aspergillus terreus. In this paper, the transport specificity of MttA is analyzed making use of different metabolically engineered Aspergillus niger strains. Furthermore, the mitochondrial localization of this protein is confirmed using fluorescence microscopy. It was found that MttA preferentially transports cis-aconitic acid over citric acid and does not transport itaconic acid. The expression of MttA in selected A. niger strains results in secretion of aconitic acid. MttA can be used in further strain engineering strategies to transport cis-aconitic acid to the cytosol to produce itaconic acid or related metabolites. The microbial production of aconitic acid (9g/L) is achieved in strains expressing this transport protein. Thus, metabolic engineering can be used for both the in vivo characterization of transport protein function like MttA and to make use of this protein by creating aconitic acid producing strains.
authors.affiliation: Austrian Centre of Industrial Biotechnology (ACIB GmbH), Muthgasse 18, Vienna, Austria; Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences Vienna, Muthgasse 18, Vienna, Austria; Institute of Biology, University Leiden, Sylviusweg 72, Leiden, The Netherlands. Electronic address: matthias.steiger@boku.ac.at.
authors.forename: Matthias G
authors.initials: MG
authors.lastname: Steiger
authors.affiliation: Institute of Biology, University Leiden, Sylviusweg 72, Leiden, The Netherlands; Dutch DNA Biotech, Utrechtseweg 48, Zeist, The Netherlands. Electronic address: peter.punt@ddna-biotech.com.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Punt
authors.affiliation: Institute of Biology, University Leiden, Sylviusweg 72, Leiden, The Netherlands. Electronic address: A.F.J.Ram@biology.leidenuniv.nl.
authors.forename: Arthur F J
authors.initials: AFJ
authors.lastname: Ram
authors.affiliation: Austrian Centre of Industrial Biotechnology (ACIB GmbH), Muthgasse 18, Vienna, Austria; Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences Vienna, Muthgasse 18, Vienna, Austria. Electronic address: diethard.mattanovich@boku.ac.at.
authors.forename: Diethard
authors.initials: D
authors.lastname: Mattanovich
authors.affiliation: Austrian Centre of Industrial Biotechnology (ACIB GmbH), Muthgasse 18, Vienna, Austria; Department of Biotechnology, BOKU - University of Natural Resources and Life Sciences Vienna, Muthgasse 18, Vienna, Austria; CD Laboratory for Biotechnology of Glycerol, Muthgasse 18, Vienna, Austria. Electronic address: michael.sauer@boku.ac.at.
authors.forename: Michael
authors.initials: M
authors.lastname: Sauer
mesh_terms: D000156:Aconitic Acid / Q000378:metabolism*; D001230:Aspergillus / Q000235:genetics / Q000378:metabolism; D001693:Biological Transport, Active / Q000235:genetics; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics; D060847:Metabolic Engineering; D024101:Mitochondrial Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D000156:Aconitic Acid
keywords: Aconitate; Aspergillus niger; Aspergillus terreus; Doxycycline; Itaconate; Itaconic acid; Mitochondrial carrier protein; Trans-aconitic acid