title: Active-Site Engineering Expands the Substrate Profile of the Basidiomycete L-Tryptophan Decarboxylase CsTDC.
abstract: Aromatic L-amino acid decarboxylases (AADCs) catalyze the release of CO2 from proteinogenic and non-proteinogenic L-amino acid substrates and are involved in pathways that biosynthesize neurotransmitters or bioactive natural products. In contrast to AADCs from animals and plants, fungal AADCs have received very little attention. Here, we report on the in vitro characterization of heterologously produced Ceriporiopsis subvermispora AADC, now referred to as CsTDC, which is the first characterized basidiomycete AADC. This study identified the enzyme as a decarboxylase that is strictly specific for L-tryptophan and 5-hydroxy-L-tryptophan. The tdc gene was subjected to saturation mutagenesis so as to vary the key active site residue, Gly351. Aliphatic amino acid residues, L-serine, or L-threonine at position 351 added L-tyrosine and 3,4-dihydroxy-L-phenylalanine (L-DOPA) decarboxylase activity while retaining stereospecificity and L-tryptophan decarboxylase activity.
authors.affiliation: Department Pharmaceutical Microbiology at the Hans-Knöll-Institute, Friedrich-Schiller-Universität, Beutenbergstrasse 11a, 07745, Jena, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kalb
authors.affiliation: Department Pharmaceutical Microbiology at the Hans-Knöll-Institute, Friedrich-Schiller-Universität, Beutenbergstrasse 11a, 07745, Jena, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Gressler
authors.affiliation: Department Pharmaceutical Microbiology at the Hans-Knöll-Institute, Friedrich-Schiller-Universität, Beutenbergstrasse 11a, 07745, Jena, Germany. dirk.hoffmeister@leibniz-hki.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hoffmeister
mesh_terms: D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000737:chemistry* / Q000235:genetics; D001487:Basidiomycota / Q000201:enzymology*; D020134:Catalytic Domain; D002851:Chromatography, High Pressure Liquid; D014644:Genetic Variation; D015394:Molecular Structure; D015202:Protein Engineering; D013379:Substrate Specificity
chemical_list: D001142:Aromatic-L-Amino-Acid Decarboxylases
keywords: amino acids; basidiomycete; enzymes; protein engineering; tryptophan decarboxylase