1kya
From Proteopedia
(New page: 200px<br /><applet load="1kya" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kya, resolution 2.40Å" /> '''ACTIVE LACCASE FROM ...) |
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| - | [[Image:1kya.gif|left|200px]]<br /><applet load="1kya" size=" | + | [[Image:1kya.gif|left|200px]]<br /><applet load="1kya" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kya, resolution 2.40Å" /> | caption="1kya, resolution 2.40Å" /> | ||
'''ACTIVE LACCASE FROM TRAMETES VERSICOLOR COMPLEXED WITH 2,5-XYLIDINE'''<br /> | '''ACTIVE LACCASE FROM TRAMETES VERSICOLOR COMPLEXED WITH 2,5-XYLIDINE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Laccases are multicopper oxidases that catalyze the oxidation of a wide | + | Laccases are multicopper oxidases that catalyze the oxidation of a wide range of phenols or arylamines, and their use in industrial oxidative processes is increasing. We purified from the white rot fungus Trametes versicolor a laccase that exists as five different isozymes, depending on glycosylation. The 2.4 A resolution structure of the most abundant isozyme of the glycosylated enzyme was solved. The four copper atoms are present, and it is the first crystal structure of a laccase in its active form. The crystallized enzyme binds 2,5-xylidine, which was used as a laccase inducer in the fungus culture. This arylamine is a very weak reducing substrate of the enzyme. The cavity enclosing 2,5-xylidine is rather wide, allowing the accommodation of substrates of various sizes. Several amino acid residues make hydrophobic interactions with the aromatic ring of the ligand. In addition, two charged or polar residues interact with its amino group. The first one is an histidine that also coordinates the copper that functions as the primary electron acceptor. The second is an aspartate conserved among fungal laccases. The purified enzyme can oxidize various hydroxylated compounds of the phenylurea family of herbicides that we synthesized. These phenolic substrates have better affinities at pH 5 than at pH 3, which could be related to the 2,5-xylidine binding by the aspartate. This is the first high-resolution structure of a multicopper oxidase complexed to a reducing substrate. It provides a model for engineering laccases that are either more efficient or with a wider substrate specificity. |
==About this Structure== | ==About this Structure== | ||
| - | 1KYA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Trametes_versicolor Trametes versicolor] with NAG, CU, PYE and XYD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Laccase Laccase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.10.3.2 1.10.3.2] Full crystallographic information is available from [http:// | + | 1KYA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Trametes_versicolor Trametes versicolor] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=CU:'>CU</scene>, <scene name='pdbligand=PYE:'>PYE</scene> and <scene name='pdbligand=XYD:'>XYD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Laccase Laccase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.10.3.2 1.10.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KYA OCA]. |
==Reference== | ==Reference== | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:39:15 2008'' |
Revision as of 11:39, 21 February 2008
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ACTIVE LACCASE FROM TRAMETES VERSICOLOR COMPLEXED WITH 2,5-XYLIDINE
Overview
Laccases are multicopper oxidases that catalyze the oxidation of a wide range of phenols or arylamines, and their use in industrial oxidative processes is increasing. We purified from the white rot fungus Trametes versicolor a laccase that exists as five different isozymes, depending on glycosylation. The 2.4 A resolution structure of the most abundant isozyme of the glycosylated enzyme was solved. The four copper atoms are present, and it is the first crystal structure of a laccase in its active form. The crystallized enzyme binds 2,5-xylidine, which was used as a laccase inducer in the fungus culture. This arylamine is a very weak reducing substrate of the enzyme. The cavity enclosing 2,5-xylidine is rather wide, allowing the accommodation of substrates of various sizes. Several amino acid residues make hydrophobic interactions with the aromatic ring of the ligand. In addition, two charged or polar residues interact with its amino group. The first one is an histidine that also coordinates the copper that functions as the primary electron acceptor. The second is an aspartate conserved among fungal laccases. The purified enzyme can oxidize various hydroxylated compounds of the phenylurea family of herbicides that we synthesized. These phenolic substrates have better affinities at pH 5 than at pH 3, which could be related to the 2,5-xylidine binding by the aspartate. This is the first high-resolution structure of a multicopper oxidase complexed to a reducing substrate. It provides a model for engineering laccases that are either more efficient or with a wider substrate specificity.
About this Structure
1KYA is a Single protein structure of sequence from Trametes versicolor with , , and as ligands. Active as Laccase, with EC number 1.10.3.2 Full crystallographic information is available from OCA.
Reference
Crystal structure of a four-copper laccase complexed with an arylamine: insights into substrate recognition and correlation with kinetics., Bertrand T, Jolivalt C, Briozzo P, Caminade E, Joly N, Madzak C, Mougin C, Biochemistry. 2002 Jun 11;41(23):7325-33. PMID:12044164
Page seeded by OCA on Thu Feb 21 13:39:15 2008
Categories: Laccase | Single protein | Trametes versicolor | Bertrand, T. | Briozzo, P. | Caminade, E. | Jolivalt, C. | Joly, N. | Madzak, C. | Mougin, C. | CU | NAG | PYE | XYD | Blue-copper | Oxidoreductase
