title: Requirement of a Functional Flavin Mononucleotide Prenyltransferase for the Activity of a Bacterial Decarboxylase in a Heterologous Muconic Acid Pathway in Saccharomyces cerevisiae.
abstract: Biotechnological production ofcis,cis-muconic acid from renewable feedstocks is an environmentally sustainable alternative to conventional, petroleum-based methods. Even though a heterologous production pathway forcis,cis-muconic acid has already been established in the host organismSaccharomyces cerevisiae, the generation of industrially relevant amounts ofcis,cis-muconic acid is hampered by the low activity of the bacterial protocatechuic acid (PCA) decarboxylase AroY isomeric subunit Ciso(AroY-Ciso), leading to secretion of large amounts of the intermediate PCA into the medium. In the present study, we show that the activity of AroY-CisoinS. cerevisiaestrongly depends on the strain background. We could demonstrate that the strain dependency is caused by the presence or absence of an intact genomic copy ofPAD1, which encodes a mitochondrial enzyme responsible for the biosynthesis of a prenylated form of the cofactor flavin mononucleotide (prFMN). The inactivity of AroY-Cisoin strain CEN.PK2-1 could be overcome by plasmid-borne expression of Pad1 or its bacterial homologue AroY subunit B (AroY-B). Our data reveal that the two enzymes perform the same function in decarboxylation of PCA by AroY-Ciso, although coexpression of Pad1 led to higher decarboxylase activity. Conversely, AroY-B can replace Pad1 in its function in decarboxylation of phenylacrylic acids by ferulic acid decarboxylase Fdc1. Targeting of the majority of AroY-B to mitochondria by fusion to a heterologous mitochondrial targeting signal did not improve decarboxylase activity of AroY-Ciso, suggesting that mitochondrial localization has no major impact on cofactor biosynthesis.IMPORTANCEInSaccharomyces cerevisiae, the decarboxylation of protocatechuic acid (PCA) to catechol is the bottleneck reaction in the heterologous biosynthetic pathway for production ofcis,cis-muconic acid, a valuable precursor for the production of bulk chemicals. In our work, we demonstrate the importance of the strain background for the activity of a bacterial PCA decarboxylase inS. cerevisiaeInactivity of the decarboxylase is due to a nonsense mutation in a gene encoding a mitochondrial enzyme involved in the biosynthesis of a cofactor required for decarboxylase function. Our study reveals functional interchangeability of Pad1 and a bacterial homologue, irrespective of their intracellular localization. Our results open up new possibilities to improve muconic acid production by engineering cofactor supply. Furthermore, the results have important implications for the choice of the production strain.
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany.
authors.forename: Heike E
authors.initials: HE
authors.lastname: Weber
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Gottardi
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Brückner
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany.
authors.forename: Mislav
authors.initials: M
authors.lastname: Oreb
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Boles
authors.affiliation: Institute of Molecular Biosciences, Goethe University, Frankfurt am Main, Germany j.tripp@bio.uni-frankfurt.de.
authors.forename: Joanna
authors.initials: J
authors.lastname: Tripp
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism*; D004122:Dimethylallyltranstransferase / Q000235:genetics / Q000378:metabolism*; D005486:Flavin Mononucleotide / Q000378:metabolism*; D062385:Hydroxybenzoates / Q000378:metabolism; D007711:Klebsiella pneumoniae / Q000201:enzymology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013011:Sorbic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D062385:Hydroxybenzoates; D029701:Saccharomyces cerevisiae Proteins; C009091:protocatechuic acid; C005939:muconic acid; D005486:Flavin Mononucleotide; D004122:Dimethylallyltranstransferase; D002262:Carboxy-Lyases; D013011:Sorbic Acid
keywords: Saccharomyces cerevisiae; biotechnology; muconic acid; phenylacrylic acid decarboxylase; prenylated flavin mononucleotide; protocatechuic acid decarboxylase; styrene