1bgn
| |||||||
| , resolution 2.0Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | POBA (Pseudomonas fluorescens) | ||||||
| Activity: | 4-hydroxybenzoate 3-monooxygenase, with EC number 1.14.13.2 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
P-HYDROXYBENZOATE HYDROXYLASE (PHBH) MUTANT WITH CYS 116 REPLACED BY SER (C116S) AND ARG 269 REPLACED BY THR (R269T), IN COMPLEX WITH FAD AND 4-HYDROXYBENZOIC ACID
OverviewOverview
The conserved residues His-162 and Arg-269 of the flavoprotein p-hydroxybenzoate hydroxylase (EC 1.14.13.2) are located at the entrance of the interdomain cleft that leads toward the active site. To study their putative role in NADPH binding, His-162 and Arg-269 were selectively changed by site-specific mutagenesis. The catalytic properties of H162R, H162Y, and R269K were similar to the wild-type enzyme. However, less conservative His-162 and Arg-269 replacements strongly impaired NADPH binding without affecting the conformation of the flavin ring and the efficiency of substrate hydroxylation. The crystal structures of H162R and R269T in complex with 4-hydroxybenzoate were solved at 3.0 and 2.0 A resolution, respectively. Both structures are virtually indistinguishable from the wild-type enzyme-substrate complex except for the substituted side chains. In contrast to wild-type p-hydroxybenzoate hydroxylase, H162R is not inactivated by diethyl pyrocarbonate. NADPH protects wild-type p-hydroxybenzoate hydroxylase from diethylpyrocarbonate inactivation, suggesting that His-162 is involved in NADPH binding. Based on these results and GRID calculations we propose that the side chains of His-162 and Arg-269 interact with the pyrophosphate moiety of NADPH. An interdomain binding mode for NADPH is proposed which takes a novel sequence motif (Eppink, M. H. M., Schreuder, H. A., and van Berkel, W. J. H. (1997) Protein Sci. 6, 2454-2458) into account.
About this StructureAbout this Structure
1BGN is a Single protein structure of sequence from Pseudomonas fluorescens. Full crystallographic information is available from OCA.
ReferenceReference
Interdomain binding of NADPH in p-hydroxybenzoate hydroxylase as suggested by kinetic, crystallographic and modeling studies of histidine 162 and arginine 269 variants., Eppink MH, Schreuder HA, van Berkel WJ, J Biol Chem. 1998 Aug 14;273(33):21031-9. PMID:9694855
Page seeded by OCA on Sun Mar 30 19:00:31 2008