Structure and biocatalytic scope of thermophilic flavin-dependent halogenase and flavin reductase enzymes

Research output: Contribution to journalArticle

  • External authors:
  • Binuraj Menon
  • Jonathan Latham
  • Mark Dunstan
  • Eileen Brandenburger
  • Ulrike Klemstein
  • Chinnan V. Karthikeyan
  • Sarah Shepherd


Flavin-dependent halogenase (Fl-Hal) enzymes have been shown to halogenate a range of synthetic as well as natural aromatic compounds. The exquisite regioselectively of Fl-Hal enzymes can provide halogenated building blocks which are inaccessible using standard halogenation chemistries. Consequently, Fl-Hal are potentially useful biocatalysts for the chemoenzymatic synthesis of pharmaceuticals and other valuable products, which are derived from haloaromatic precursors. However, the application of Fl-Hal enzymes, in vitro, has been hampered by their poor catalytic activity and lack of stability. To overcome these issues, we identified a thermophilic tryptophan halogenase (Th-Hal), which has significantly improved catalytic activity and stability, compared with other Fl-Hal characterised to date. When used in combination with a thermostable flavin reductase, Th-Hal can efficiently halogenate a number of aromatic substrates. X-ray crystal structures of Th-Hal, and the reductase partner (Th-Fre), provide insights into the factors that contribute to enzyme stability, which could guide the discovery and engineering of more robust and productive halogenase biocatalysts.

Bibliographical metadata

Original languageEnglish
Pages (from-to)9354-9361
JournalOrganic and Biomolecular Chemistry
Early online date6 Sep 2016
StatePublished - 6 Sep 2016