Discovery and Functional Characterization of SnFDHal, an Efficient Tryptophan 5-Halogenase from Streptomyces noursei
Year: 2025
Type: article
Abstract: Flavin-dependent halogenases (FDHs) are a class of enzymes renowned for their regioselective ability to precisely insert halogen atoms into small aromatic compounds. Halogen incorporation can enhance the physicochemical and biological properties of molecules, making them valuable for agrochemical and pharmaceutical applications. Through bioinformatic mining of bacterial genomes, we discovered and functionally characterized SnFDHal, an efficient tryptophan 5-halogenase from Streptomyces noursei NRRL B-1714. This halogenase operates across a broad pH range and exhibits a melting temperature of 46.7 °C at both pH 6 and pH 8, which is comparable to thermophilic halogenases such as Th-Hal and BorH, and notably higher than those of mesophilic counterparts. Steady-state kinetic analysis revealed that SnFDHal displays superior catalytic efficiency for the chlorination of L-tryptophan compared to other FDHs reported to date. Structural modeling of its active site suggests that a conserved bulky phenylalanine residue (F49) promotes halogenation at the C-5 position of L-tryptophan, consistent with experimental findings. The combination of high catalytic efficiency and thermostability positions SnFDHal as a promising biocatalyst for applications in agrochemical and pharmaceutical industries.
Institutions: Utah State University, The University of Texas at Austin
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,890
OpenAlex ID: W4416024279