2ar8
From Proteopedia
The structure of tryptophan 7-halogenase (PrnA)suggests a mechanism for regioselective chlorination
Overview
Chlorinated natural products include vancomycin and cryptophycin A. Their biosynthesis involves regioselective chlorination by flavin-dependent halogenases. We report the structural characterization of tryptophan 7-halogenase (PrnA), which regioselectively chlorinates tryptophan. Tryptophan and flavin adenine dinucleotide (FAD) are separated by a 10 angstrom-long tunnel and bound by distinct enzyme modules. The FAD module is conserved in halogenases and is related to flavin-dependent monooxygenases. On the basis of biochemical studies, crystal structures, and by analogy with monooxygenases, we predict that FADH2 reacts with O2 to make peroxyflavin, which is decomposed by Cl-. The resulting HOCl is guided through the tunnel to tryptophan, where it is activated to participate in electrophilic aromatic substitution.
About this Structure
2AR8 is a Single protein structure of sequence from Pseudomonas fluorescens. Full crystallographic information is available from OCA.
Reference
Tryptophan 7-halogenase (PrnA) structure suggests a mechanism for regioselective chlorination., Dong C, Flecks S, Unversucht S, Haupt C, van Pee KH, Naismith JH, Science. 2005 Sep 30;309(5744):2216-9. PMID:16195462 Page seeded by OCA on Sat May 3 19:22:30 2008
Categories: Pseudomonas fluorescens | Single protein | Dong, C. | Flecks, S. | Haupt, C. | Naismith, J H. | Pee, K H.Van. | SSPF, Scottish Structural Proteomics Facility. | Unversucht, S. | Helical bundle | Sandwiched sheet | Scottish structural proteomics facility | Sspf | Structural genomic | Tryptophan 7-halogenase,flavin-dependent halogenase
