1yiy
From Proteopedia
(New page: 200px<br /><applet load="1yiy" size="450" color="white" frame="true" align="right" spinBox="true" caption="1yiy, resolution 1.9Å" /> '''Aedes aegypti kynuren...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1yiy.gif|left|200px]]<br /><applet load="1yiy" size=" | + | [[Image:1yiy.gif|left|200px]]<br /><applet load="1yiy" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1yiy, resolution 1.9Å" /> | caption="1yiy, resolution 1.9Å" /> | ||
'''Aedes aegypti kynurenine aminotransferase'''<br /> | '''Aedes aegypti kynurenine aminotransferase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Aedes aegypti kynurenine aminotransferase (AeKAT) catalyzes the | + | Aedes aegypti kynurenine aminotransferase (AeKAT) catalyzes the irreversible transamination of kynurenine to kynurenic acid, the natural antagonist of NMDA and 7-nicotinic acetycholine receptors. Here, we report the crystal structure of AeKAT in its PMP and PLP forms at 1.90 and 1.55 A, respectively. The structure was solved by a combination of single-wavelength anomalous dispersion and molecular replacement approaches. The initial search model in the molecular replacement method was built with the result of single-wavelength anomalous dispersion data from the Br-AeKAT crystal in combination with homology modeling. The solved structure shows that the enzyme is a homodimer, and that the two subunits are stabilized by a number of hydrogen bonds, salts bridges, and hydrophobic interactions. Each subunit is divided into an N-terminal arm and small and large domains. Based on its folding, the enzyme belongs to the prototypical fold type, aminotransferase subgroup I. The three-dimensional structure shows a strictly conserved 'PLP-phosphate binding cup' featuring PLP-dependent enzymes. The interaction between Cys284 (A) and Cys284 (B) is unique in AeKAT, which might explain the cysteine effect of AeKAT activity. Further mutation experiments of this residue are needed to eventually understand the mechanism of the enzyme modulation by cysteine. |
==About this Structure== | ==About this Structure== | ||
| - | 1YIY is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aedes_aegypti Aedes aegypti] with BR and PMP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1YIY is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aedes_aegypti Aedes aegypti] with <scene name='pdbligand=BR:'>BR</scene> and <scene name='pdbligand=PMP:'>PMP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YIY OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Ding, H.]] | [[Category: Ding, H.]] | ||
| - | [[Category: Gao, Y | + | [[Category: Gao, Y G.]] |
[[Category: Han, Q.]] | [[Category: Han, Q.]] | ||
[[Category: Li, J.]] | [[Category: Li, J.]] | ||
| Line 31: | Line 31: | ||
[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:05:50 2008'' |
Revision as of 14:05, 21 February 2008
|
Aedes aegypti kynurenine aminotransferase
Overview
Aedes aegypti kynurenine aminotransferase (AeKAT) catalyzes the irreversible transamination of kynurenine to kynurenic acid, the natural antagonist of NMDA and 7-nicotinic acetycholine receptors. Here, we report the crystal structure of AeKAT in its PMP and PLP forms at 1.90 and 1.55 A, respectively. The structure was solved by a combination of single-wavelength anomalous dispersion and molecular replacement approaches. The initial search model in the molecular replacement method was built with the result of single-wavelength anomalous dispersion data from the Br-AeKAT crystal in combination with homology modeling. The solved structure shows that the enzyme is a homodimer, and that the two subunits are stabilized by a number of hydrogen bonds, salts bridges, and hydrophobic interactions. Each subunit is divided into an N-terminal arm and small and large domains. Based on its folding, the enzyme belongs to the prototypical fold type, aminotransferase subgroup I. The three-dimensional structure shows a strictly conserved 'PLP-phosphate binding cup' featuring PLP-dependent enzymes. The interaction between Cys284 (A) and Cys284 (B) is unique in AeKAT, which might explain the cysteine effect of AeKAT activity. Further mutation experiments of this residue are needed to eventually understand the mechanism of the enzyme modulation by cysteine.
About this Structure
1YIY is a Single protein structure of sequence from Aedes aegypti with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structures of Aedes aegypti kynurenine aminotransferase., Han Q, Gao YG, Robinson H, Ding H, Wilson S, Li J, FEBS J. 2005 May;272(9):2198-206. PMID:15853804
Page seeded by OCA on Thu Feb 21 16:05:50 2008
Categories: Aedes aegypti | Single protein | Ding, H. | Gao, Y G. | Han, Q. | Li, J. | Robinson, H. | Wilson, S. | BR | PMP | Aedes | Kynurenic acid | Kynurenine | Kynurenine aminotrasferase | Mosquito | Plp-enzyme | Pmp | Pyridoxamine phosphate | Transferase
