Biosynthesis of Violacein, Structure and Function of l-Tryptophan Oxidase VioA from Chromobacterium violaceum.
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
AuthorsFüller, Janis J
Rennhack, Kim E
Daniel, Nils P
MetadataShow full item record
AbstractViolacein is a natural purple pigment of Chromobacterium violaceum with potential medical applications as antimicrobial, antiviral, and anticancer drugs. The initial step of violacein biosynthesis is the oxidative conversion of l-tryptophan into the corresponding α-imine catalyzed by the flavoenzyme l-tryptophan oxidase (VioA). A substrate-related (3-(1H-indol-3-yl)-2-methylpropanoic acid) and a product-related (2-(1H-indol-3-ylmethyl)prop-2-enoic acid) competitive VioA inhibitor was synthesized for subsequent kinetic and x-ray crystallographic investigations. Structures of the binary VioA·FADH2 and of the ternary VioA·FADH2·2-(1H-indol-3-ylmethyl)prop-2-enoic acid complex were resolved. VioA forms a "loosely associated" homodimer as indicated by small-angle x-ray scattering experiments. VioA belongs to the glutathione reductase family 2 of FAD-dependent oxidoreductases according to the structurally conserved cofactor binding domain. The substrate-binding domain of VioA is mainly responsible for the specific recognition of l-tryptophan. Other canonical amino acids were efficiently discriminated with a minor conversion of l-phenylalanine. Furthermore, 7-aza-tryptophan, 1-methyl-tryptophan, 5-methyl-tryptophan, and 5-fluoro-tryptophan were efficient substrates of VioA. The ternary product-related VioA structure indicated involvement of protein domain movement during enzyme catalysis. Extensive structure-based mutagenesis in combination with enzyme kinetics (using l-tryptophan and substrate analogs) identified Arg(64), Lys(269), and Tyr(309) as key catalytic residues of VioA. An increased enzyme activity of protein variant H163A in the presence of l-phenylalanine indicated a functional role of His(163) in substrate binding. The combined structural and mutational analyses lead to the detailed understanding of VioA substrate recognition. Related strategies for the in vivo synthesis of novel violacein derivatives are discussed.
CitationBiosynthesis of Violacein, Structure and Function of l-Tryptophan Oxidase VioA from Chromobacterium violaceum. 2016, 291 (38):20068-84 J. Biol. Chem.
AffiliationHelmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany.
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc-sa/4.0/
- In vitro biosynthesis of violacein from L-tryptophan by the enzymes VioA-E from Chromobacterium violaceum.
- Authors: Balibar CJ, Walsh CT
- Issue date: 2006 Dec 26
- Sequence analysis and functional characterization of the violacein biosynthetic pathway from Chromobacterium violaceum.
- Authors: August PR, Grossman TH, Minor C, Draper MP, MacNeil IA, Pemberton JM, Call KM, Holt D, Osburne MS
- Issue date: 2000 Oct
- Protein engineering for improving the thermostability of tryptophan oxidase and insights from structural analysis.
- Authors: Yamaguchi H, Tatsumi M, Takahashi K, Tagami U, Sugiki M, Kashiwagi T, Kameya M, Okazaki S, Mizukoshi T, Asano Y
- Issue date: 2018 Nov 1
- Violacein and related tryptophan metabolites produced by Chromobacterium violaceum: biosynthetic mechanism and pathway for construction of violacein core.
- Authors: Hoshino T
- Issue date: 2011 Sep
- Crystal structure of VioE, a key player in the construction of the molecular skeleton of violacein.
- Authors: Hirano S, Asamizu S, Onaka H, Shiro Y, Nagano S
- Issue date: 2008 Mar 7