title: Characterization of TioF, a tryptophan 2,3-dioxygenase involved in 3-hydroxyquinaldic acid formation during thiocoraline biosynthesis.
abstract: Thiocoraline is a thiodepsipeptide antitumor agent that belongs to the family of bisintercalator natural products that bind duplex DNA through their two planar intercalating moieties. In thiocoraline, the 3-hydroxyquinaldic acid (3HQA) chromophores required for intercalation are derived from L-Trp. We have expressed the Micromonospora sp. ML1 tryptophan 2,3-dioxygenase(TDO) TioF, purified it from E. coli, and confirmed its role in the irreversible oxidation of L-Trp to N-formylkynurenine, the proposed first step during 3HQA biosynthesis. We have established that TioF is a catalyst with broader specificity than other TDOs, but that is less promiscuous than indoleamine 2,3-dioxygenases. TioF was found to display activity with various L-Trp analogs (serotonin, D-Trp, and indole). The TioF reaction products generated during this study will be used as substrates for subsequent analysis of the other enzymes involved in 3HQA biosynthesis.
authors.affiliation: University of Michigan, Department of Medicinal Chemistry in the College of Pharmacy and the Life Sciences Institute, 210 Washtenaw Ave, Ann Arbor, MI 48109, USA.
authors.forename: Anita
authors.initials: A
authors.lastname: Sheoran
authors.forename: Andrew
authors.initials: A
authors.lastname: King
authors.forename: Ana
authors.initials: A
authors.lastname: Velasco
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Pero
authors.forename: Sylvie
authors.initials: S
authors.lastname: Garneau-Tsodikova
mesh_terms: D047630:Depsipeptides / Q000096:biosynthesis* / Q000737:chemistry; D004789:Enzyme Activation; D007700:Kinetics; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D008847:Micromonospora / Q000201:enzymology; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D013379:Substrate Specificity; D014366:Tryptophan Oxygenase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: C533875:3-hydroxyquinaldic acid; D047630:Depsipeptides; C109005:thiocoraline; D014366:Tryptophan Oxygenase; D007736:Kynurenic Acid