1bf3: Difference between revisions
From Proteopedia
Jump to navigationJump to search
New page: left|200px<br /><applet load="1bf3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bf3, resolution 2.2Å" /> '''P-HYDROXYBENZOATE HYD... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1bf3.gif|left|200px]]<br /><applet load="1bf3" size=" | [[Image:1bf3.gif|left|200px]]<br /><applet load="1bf3" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1bf3, resolution 2.2Å" /> | caption="1bf3, resolution 2.2Å" /> | ||
'''P-HYDROXYBENZOATE HYDROXYLASE (PHBH) MUTANT WITH CYS 116 REPLACED BY SER (C116S) AND ARG 42 REPLACED BY LYS (R42K), IN COMPLEX WITH FAD AND 4-HYDROXYBENZOIC ACID'''<br /> | '''P-HYDROXYBENZOATE HYDROXYLASE (PHBH) MUTANT WITH CYS 116 REPLACED BY SER (C116S) AND ARG 42 REPLACED BY LYS (R42K), IN COMPLEX WITH FAD AND 4-HYDROXYBENZOIC ACID'''<br /> | ||
==Overview== | ==Overview== | ||
The conserved Arg42 of the flavoprotein p-hydroxybenzoate hydroxylase is | The conserved Arg42 of the flavoprotein p-hydroxybenzoate hydroxylase is located at the entrance of the active site in a loop between helix H2 and sheet E1 of the FAD-binding domain. Replacement of Arg42 by Lys or Ser decreases the turnover rate of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens by more than two orders of magnitude. Rapid reaction kinetics show that the low activity of the Arg42 variants results from impaired binding of NADPH. In contrast to an earlier conclusion drawn for p-hydroxybenzoate hydroxylase from Acinetobacter calcoaceticus, substitution of Arg42 with Ser42 in the enzyme from P. fluorescens hardly disturbs the binding of FAD. Crystals of [Lys42]p-hydroxybenzoate hydroxylase complexed with 4-hydroxybenzoate diffract to 0.22-nm resolution. The structure of the Lys42 variant is virtually indistinguishable from the native enzyme with the flavin ring occupying the interior position within the active site. Lys42 in the mutant structure interacts indirectly via a solvent molecule with the 3-OH of the adenosine ribose moiety of FAD. Substrate perturbation difference spectra suggest that the Arg42 replacements influence the solvent accessibility of the flavin ring in the oxidized enzyme. In spite of this, the Arg42 variants fully couple enzyme reduction to substrate hydroxylation. Sequence-comparison studies suggest that Arg42 is involved in binding of the 2'-phosphoadenosine moiety of NADPH. | ||
==About this Structure== | ==About this Structure== | ||
1BF3 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:// | 1BF3 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 <scene name='pdbligand=FAD:'>FAD</scene> and <scene name='pdbligand=PHB:'>PHB</scene> 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://oca.weizmann.ac.il/oca-bin/ocashort?id=1BF3 OCA]. | ||
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Pseudomonas fluorescens]] | [[Category: Pseudomonas fluorescens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Berkel, W | [[Category: Berkel, W J.H Van.]] | ||
[[Category: Eppink, M | [[Category: Eppink, M H.M.]] | ||
[[Category: Schreuder, H | [[Category: Schreuder, H A.]] | ||
[[Category: FAD]] | [[Category: FAD]] | ||
[[Category: PHB]] | [[Category: PHB]] | ||
[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:54:38 2008'' | ||