1ks4
From Proteopedia
(New page: 200px<br /><applet load="1ks4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ks4, resolution 2.5Å" /> '''The structure of Aspe...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1ks4.gif|left|200px]]<br /><applet load="1ks4" size=" | + | [[Image:1ks4.gif|left|200px]]<br /><applet load="1ks4" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ks4, resolution 2.5Å" /> | caption="1ks4, resolution 2.5Å" /> | ||
'''The structure of Aspergillus niger endoglucanase-palladium complex'''<br /> | '''The structure of Aspergillus niger endoglucanase-palladium complex'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The fungus Aspergillus niger is a main source of industrial cellulase. | + | The fungus Aspergillus niger is a main source of industrial cellulase. beta-1,4-Endoglucanase is the major component of cellulase from A. niger. In spite of widespread applications, little is known about the structure of this enzyme. Here, the structure of beta-1,4-endoglucanase from A. niger (EglA) was determined at 2.1 A resolution. Although there is a low sequence identity between EglA and CelB2, another member of family 12, the three-dimensional structures of their core regions are quite similar. The structural differences are mostly found in the loop regions, where CelB2 has an extra beta-sheet (beta-sheet C) at the non-reducing end of the binding cleft of the native enzyme. Incubation of EglA with PdCl(2) irreversibly inhibits the EglA activity. Structural studies of the enzyme-palladium complex show that three Pd(2+) ions bind to each EglA molecule. One of the Pd(2+) ions forms a coordinate covalent bond with Met118 S(delta) and the nucleophilic Glu116 O(epsilon1) at the active site of the enzyme. The other two Pd(2+) ions bind on the surface of the protein. Binding of Pd(2+) ions to EglA does not change the general conformation of the backbone of the protein significantly. Based on this structural study, one can conclude that the palladium ion directly binds to and blocks the active site of EglA and thus inactivates the enzyme. |
==About this Structure== | ==About this Structure== | ||
| - | 1KS4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_niger Aspergillus niger] with PD as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Cellulase Cellulase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.4 3.2.1.4] Full crystallographic information is available from [http:// | + | 1KS4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_niger Aspergillus niger] with <scene name='pdbligand=PD:'>PD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Cellulase Cellulase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.4 3.2.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KS4 OCA]. |
==Reference== | ==Reference== | ||
| Line 27: | Line 27: | ||
[[Category: family 9]] | [[Category: family 9]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:37:19 2008'' |
Revision as of 11:37, 21 February 2008
|
The structure of Aspergillus niger endoglucanase-palladium complex
Overview
The fungus Aspergillus niger is a main source of industrial cellulase. beta-1,4-Endoglucanase is the major component of cellulase from A. niger. In spite of widespread applications, little is known about the structure of this enzyme. Here, the structure of beta-1,4-endoglucanase from A. niger (EglA) was determined at 2.1 A resolution. Although there is a low sequence identity between EglA and CelB2, another member of family 12, the three-dimensional structures of their core regions are quite similar. The structural differences are mostly found in the loop regions, where CelB2 has an extra beta-sheet (beta-sheet C) at the non-reducing end of the binding cleft of the native enzyme. Incubation of EglA with PdCl(2) irreversibly inhibits the EglA activity. Structural studies of the enzyme-palladium complex show that three Pd(2+) ions bind to each EglA molecule. One of the Pd(2+) ions forms a coordinate covalent bond with Met118 S(delta) and the nucleophilic Glu116 O(epsilon1) at the active site of the enzyme. The other two Pd(2+) ions bind on the surface of the protein. Binding of Pd(2+) ions to EglA does not change the general conformation of the backbone of the protein significantly. Based on this structural study, one can conclude that the palladium ion directly binds to and blocks the active site of EglA and thus inactivates the enzyme.
About this Structure
1KS4 is a Single protein structure of sequence from Aspergillus niger with as ligand. Active as Cellulase, with EC number 3.2.1.4 Full crystallographic information is available from OCA.
Reference
Determination of the structure of an endoglucanase from Aspergillus niger and its mode of inhibition by palladium chloride., Khademi S, Zhang D, Swanson SM, Wartenberg A, Witte K, Meyer EF, Acta Crystallogr D Biol Crystallogr. 2002 Apr;58(Pt 4):660-7. Epub 2002, Mar 22. PMID:11914491
Page seeded by OCA on Thu Feb 21 13:37:19 2008
