1knr
From Proteopedia
(New page: 200px<br /><applet load="1knr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1knr, resolution 2.500Å" /> '''L-aspartate oxidase...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1knr.gif|left|200px]]<br /><applet load="1knr" size=" | + | [[Image:1knr.gif|left|200px]]<br /><applet load="1knr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1knr, resolution 2.500Å" /> | caption="1knr, resolution 2.500Å" /> | ||
'''L-aspartate oxidase: R386L mutant'''<br /> | '''L-aspartate oxidase: R386L mutant'''<br /> | ||
==Overview== | ==Overview== | ||
| - | L-Aspartate oxidase (Laspo) catalyzes the conversion of L-Asp to | + | L-Aspartate oxidase (Laspo) catalyzes the conversion of L-Asp to iminoaspartate, the first step in the de novo biosynthesis of NAD(+). This bacterial pathway represents a potential drug target since it is absent in mammals. The Laspo R386L mutant was crystallized in the FAD-bound catalytically competent form and its three-dimensional structure determined at 2.5 A resolution in both the native state and in complex with succinate. Comparison of the R386L holoprotein with the wild-type apoenzyme [Mattevi, A., Tedeschi, G., Bacchella, L., Coda, A., Negri, A., and Ronchi, S. (1999) Structure 7, 745-756] reveals that cofactor incorporation leads to the ordering of two polypeptide segments (residues 44-53 and 104-141) and to a 27 degree rotation of the capping domain. This motion results in the formation of the active site cavity, located at the interface between the capping domain and the FAD-binding domain. The structure of the succinate complex indicates that the cavity surface is decorated by two clusters of H-bond donors that anchor the ligand carboxylates. Moreover, Glu121, which is strictly conserved among Laspo sequences, is positioned to interact with the L-Asp alpha-amino group. The architecture of the active site of the Laspo holoenzyme is remarkably similar to that of respiratory fumarate reductases, providing strong evidence for a common mechanism of catalysis in Laspo and flavoproteins of the succinate dehydrogenase/fumarate reductase family. This implies that Laspo is mechanistically distinct from other flavin-dependent amino acid oxidases, such as the prototypical D-amino acid oxidase. |
==About this Structure== | ==About this Structure== | ||
| - | 1KNR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CL, NA and FAD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-aspartate_oxidase L-aspartate oxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.4.3.16 1.4.3.16] Full crystallographic information is available from [http:// | + | 1KNR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=CL:'>CL</scene>, <scene name='pdbligand=NA:'>NA</scene> and <scene name='pdbligand=FAD:'>FAD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-aspartate_oxidase L-aspartate oxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.4.3.16 1.4.3.16] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KNR OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: L-aspartate oxidase]] | [[Category: L-aspartate oxidase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Bossi, R | + | [[Category: Bossi, R T.]] |
[[Category: Mattevi, A.]] | [[Category: Mattevi, A.]] | ||
[[Category: CL]] | [[Category: CL]] | ||
| Line 22: | Line 22: | ||
[[Category: succinate dehydrogenase]] | [[Category: succinate dehydrogenase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:36:03 2008'' |
Revision as of 11:36, 21 February 2008
|
L-aspartate oxidase: R386L mutant
Overview
L-Aspartate oxidase (Laspo) catalyzes the conversion of L-Asp to iminoaspartate, the first step in the de novo biosynthesis of NAD(+). This bacterial pathway represents a potential drug target since it is absent in mammals. The Laspo R386L mutant was crystallized in the FAD-bound catalytically competent form and its three-dimensional structure determined at 2.5 A resolution in both the native state and in complex with succinate. Comparison of the R386L holoprotein with the wild-type apoenzyme [Mattevi, A., Tedeschi, G., Bacchella, L., Coda, A., Negri, A., and Ronchi, S. (1999) Structure 7, 745-756] reveals that cofactor incorporation leads to the ordering of two polypeptide segments (residues 44-53 and 104-141) and to a 27 degree rotation of the capping domain. This motion results in the formation of the active site cavity, located at the interface between the capping domain and the FAD-binding domain. The structure of the succinate complex indicates that the cavity surface is decorated by two clusters of H-bond donors that anchor the ligand carboxylates. Moreover, Glu121, which is strictly conserved among Laspo sequences, is positioned to interact with the L-Asp alpha-amino group. The architecture of the active site of the Laspo holoenzyme is remarkably similar to that of respiratory fumarate reductases, providing strong evidence for a common mechanism of catalysis in Laspo and flavoproteins of the succinate dehydrogenase/fumarate reductase family. This implies that Laspo is mechanistically distinct from other flavin-dependent amino acid oxidases, such as the prototypical D-amino acid oxidase.
About this Structure
1KNR is a Single protein structure of sequence from Escherichia coli with , and as ligands. Active as L-aspartate oxidase, with EC number 1.4.3.16 Full crystallographic information is available from OCA.
Reference
Structure of FAD-bound L-aspartate oxidase: insight into substrate specificity and catalysis., Bossi RT, Negri A, Tedeschi G, Mattevi A, Biochemistry. 2002 Mar 5;41(9):3018-24. PMID:11863440
Page seeded by OCA on Thu Feb 21 13:36:03 2008
