Crystallization and X-ray diffraction of a halogenating enzyme, tryptophan 7-halogenase, from Pseudomonas fluorescens.
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.
Centre for Biomolecular Sciences, University of St Andrews, North Haugh, Fife KY16 9ST, Scotland.
Changjiang
C
Dong
Alexander
A
Kotzsch
Mark
M
Dorward
Karl Heinz
KH
van Pée
James H
JH
Naismith
D003460:Crystallization; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D011764:Pyrrolnitrin / Q000096:biosynthesis / Q000737:chemistry
D010088:Oxidoreductases; C407363:tryptophan halogenase; D011764:Pyrrolnitrin