Flavin-dependent halogenases (FDHs) have tremendous applications in synthetic chemistry. A single-component FDH, AetF, exhibits both halogenase and reductase activities in a continuous polypeptide chain. AetF exhibits broad substrate promiscuity and catalyzes the two-step bromination of l-tryptophan (l-Trp) to produce 5-bromotryptophan (5-Br-Trp) and 5,7-dibromo-l-tryptophan (5,7-di-Br-Trp). To elucidate the mechanism of action of AetF, we solved its crystal structure in complex with FAD, FAD/NADP, FAD/l-Trp, and FAD/5-Br-Trp at resolutions of 1.92-2.23 Å. The obtained crystal structures depict the unprecedented topology of single-component FDH. Structural analysis revealed that the substrate flexibility and dibromination capability of AetF could be attributed to its spacious substrate-binding pocket. In addition, highly-regulated interaction networks between the substrate-recognizing residues and 5-Br-Trp are crucial for the dibromination activity of AetF. Several Ala variants underwent monobromination with >98 % C5-regioselectivity toward l-Trp. These results reveal the catalytic mechanism of single-component FDH for the first time and contribute to efficient FDH protein engineering for biocatalytic halogenation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ijbiomac.2024.129312 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Identifying and Engineering Flavin Dependent Halogenases for Selective Biocatalysis.
Acc Chem Res
August 2024
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States.
ConspectusOrganohalogen compounds are extensively used as building blocks, intermediates, pharmaceuticals, and agrochemicals due to their unique chemical and biological properties. Installing halogen substituents, however, frequently requires functionalized starting materials and multistep functional group interconversion. Several classes of halogenases evolved in nature to enable halogenation of a different classes of substrates; for example, site-selective halogenation of electron rich aromatic compounds is catalyzed by flavin-dependent halogenases (FDHs).
View Article and Find Full Text PDFSelective C-H Halogenation of Alkenes and Alkynes Using Flavin-Dependent Halogenases.
Angew Chem Int Ed Engl
March 2024
Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
Single component flavin-dependent halogenases (FDHs) possess both flavin reductase and FDH activity in a single enzyme. We recently reported that the single component FDH AetF catalyzes site-selective bromination and iodination of a variety of aromatic substrates and enantioselective bromolactonization and iodoetherification of styrenes bearing pendant carboxylic acid or alcohol substituents. Given this inherent reactivity and selectivity, we explored the utility of AetF as catalyst for alkene and alkyne C-H halogenation.
View Article and Find Full Text PDFStructural and functional insights into the self-sufficient flavin-dependent halogenase.
Int J Biol Macromol
March 2024
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Hongshan Laboratory, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China; Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou 311121, PR China. Electronic address:
Flavin-dependent halogenases (FDHs) have tremendous applications in synthetic chemistry. A single-component FDH, AetF, exhibits both halogenase and reductase activities in a continuous polypeptide chain. AetF exhibits broad substrate promiscuity and catalyzes the two-step bromination of l-tryptophan (l-Trp) to produce 5-bromotryptophan (5-Br-Trp) and 5,7-dibromo-l-tryptophan (5,7-di-Br-Trp).
View Article and Find Full Text PDFStructural basis of regioselective tryptophan dibromination by the single-component flavin-dependent halogenase AetF.
Acta Crystallogr D Struct Biol
July 2023
Department of Chemistry, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld, Germany.
The flavin-dependent halogenase (FDH) AetF successively brominates tryptophan at C5 and C7 to generate 5,7-dibromotryptophan. In contrast to the well studied two-component tryptophan halogenases, AetF is a single-component flavoprotein monooxygenase. Here, crystal structures of AetF alone and in complex with various substrates are presented, representing the first experimental structures of a single-component FDH.
View Article and Find Full Text PDFAsymmetric catalysis by flavin-dependent halogenases.
Chirality
August 2023
Department of Chemistry, Indiana University, Bloomington, Indiana, USA.
In nature, flavin-dependent halogenases (FDHs) catalyze site-selective chlorination and bromination of aromatic natural products. This ability has led to extensive efforts to engineer FDHs for selective chlorination, bromination, and iodination of electron rich aromatic compounds. On the other hand, FDHs are unique among halogenases and haloperoxidases that exhibit catalyst-controlled site selectivity in that no examples of enantioselective FDH catalysis in natural product biosynthesis have been characterized.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!