View source for 1cj3

[[Image:1cj3.gif|left|200px]]<br /><applet load="1cj3" size="450" color="white" frame="true" align="right" spinBox="true" 
caption="1cj3, resolution 2.5&Aring;" />
'''MUTANT TYR38GLU OF PARA-HYDROXYBENZOATE HYDROXYLASE'''<br />

==Overview==
p-Hydroxybenzoate hydroxylase (PHBH) is the archetype of the family of, NAD(P)H-dependent flavoprotein aromatic hydroxylases. These enzymes share, a conserved FAD-binding domain but lack a recognizable fold for binding, the pyridine nucleotide. We have switched the coenzyme specificity of, strictly NADPH-dependent PHBH from Pseudomonas fluorescens by, site-directed mutagenesis. To that end, we altered the solvent exposed, helix H2 region (residues 33-40) of the FAD-binding domain., Non-conservative selective replacements of Arg33 and Tyr38 weakened the, binding of NADPH without disturbing the protein architecture. Introduction, of a basic residue at position 34 increased the NADPH binding strength., Double (M2) and quadruple (M4) substitutions in the N-terminal part of, helix H2 did not change the coenzyme specificity. By extending the, replacements towards residues 38 and 40, M5 and M6 mutants were generated, which were catalytically more efficient with NADH than with NADPH. It is, concluded that specificity in P. fluorescens PHBH is conferred by, interactions of Arg33, Tyr38 and Arg42 with the 2'-phosphate moiety of, bound NADPH, and that introduction of an acidic group at position 38, potentially enables the recognition of the 2'-hydroxy group of NADH. This, is the first report on the coenzyme reversion of a flavoprotein aromatic, hydroxylase.

==About this Structure==
1CJ3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_fluorescens Pseudomonas fluorescens] with FAD and PHB as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/4-hydroxybenzoate_3-monooxygenase 4-hydroxybenzoate 3-monooxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.2 1.14.13.2] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1CJ3 OCA]. 

==Reference==
Switch of coenzyme specificity of p-hydroxybenzoate hydroxylase., Eppink MH, Overkamp KM, Schreuder HA, Van Berkel WJ, J Mol Biol. 1999 Sep 10;292(1):87-96. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10493859 10493859]
[[Category: 4-hydroxybenzoate 3-monooxygenase]]
[[Category: Pseudomonas fluorescens]]
[[Category: Single protein]]
[[Category: Berkel, W.J.H.Van.]]
[[Category: Eppink, M.H.M.]]
[[Category: Overkamp, K.M.]]
[[Category: Schreuder, H.A.]]
[[Category: FAD]]
[[Category: PHB]]
[[Category: hydroxybenzoate]]
[[Category: oxidoreductase]]

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:30:25 2007''