Crystallization and X-ray diffraction of a halogenating enzyme, tryptophan 7-halogenase, from Pseudomonas fluorescens

Changjiang Dong, Alexander Kotzsch, Mark Dorward, Karl Heinz van Pée, James H Naismith

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Chlorination of natural products is often required for their biological activity; notable examples include vancomycin, the last-ditch antibiotic. It is now known that many chlorinated natural products are made not by haloperoxidases, but by FADH2-dependent halogenases. The mechanism of the flavin-containing enzymes is obscure and there are no structural data. Here, crystals of PrnA (tryptophan 7-halogenase), an enzyme that regioselectively chlorinates tryptophan, cocrystallized with tryptophan and FAD are reported. The crystals belong to the tetragonal space group P4(3)2(1)2 or P4(1)2(1)2, with unit-cell parameters a = b = 67.8, c = 276.9 A. A data set to 1.8 A with 93% completeness and an Rmerge of 7.1% has been collected from a single flash-cooled crystal. A method for incorporating selenomethionine in a Pseudomonas fluorescens expression system also is reported.
Original languageEnglish
Pages (from-to)1438-40
Number of pages3
JournalActa Crystallographica Section D: Biological Crystallography
Issue numberPt 8
Publication statusPublished - Aug 2004


  • Crystallization
  • Crystallography, X-Ray
  • Molecular Structure
  • Oxidoreductases
  • Pseudomonas fluorescens
  • Pyrrolnitrin

Cite this