1m7j
From Proteopedia
(New page: 200px<br /><applet load="1m7j" size="450" color="white" frame="true" align="right" spinBox="true" caption="1m7j, resolution 1.5Å" /> '''Crystal structure of ...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1m7j.jpg|left|200px]]<br /><applet load="1m7j" size=" | + | [[Image:1m7j.jpg|left|200px]]<br /><applet load="1m7j" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1m7j, resolution 1.5Å" /> | caption="1m7j, resolution 1.5Å" /> | ||
'''Crystal structure of D-aminoacylase defines a novel subset of amidohydrolases'''<br /> | '''Crystal structure of D-aminoacylase defines a novel subset of amidohydrolases'''<br /> | ||
==Overview== | ==Overview== | ||
| - | D-Aminoacylase is an attractive candidate for commercial production of | + | D-Aminoacylase is an attractive candidate for commercial production of D-amino acids through its catalysis in the hydrolysis of N-acyl-D-amino acids. We report here the first D-aminoacylase crystal structure from A. faecalis at 1.5-A resolution. The protein comprises a small beta-barrel, and a catalytic (betaalpha)(8)-barrel with a 63-residue insertion. The enzyme structure shares significant similarity to the alpha/beta-barrel amidohydrolase superfamily, in which the beta-strands in both barrels superimpose well. Unexpectedly, the enzyme binds two zinc ions with widely different affinities, although only the tightly bound zinc ion is required for activity. One zinc ion is coordinated by Cys(96), His(220), and His(250), while the other is loosely chelated by His(67), His(69), and Cys(96). This is the first example of the metal ion coordination by a cysteine residue in the superfamily. Therefore, D-aminoacylase defines a novel subset and is a mononuclear zinc metalloenzyme but containing a binuclear active site. The preferred substrate was modeled into a hydrophobic pocket, revealing the substrate specificity and enzyme catalysis. The 63-residue insertion containing substrate-interacting residues may act as a gate controlling access to the active site, revealing that the substrate binding would induce a closed conformation to sequester the catalysis from solvent. |
==About this Structure== | ==About this Structure== | ||
| - | 1M7J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis] with ZN and ACT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/N-acyl-D-amino-acid_deacylase N-acyl-D-amino-acid deacylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.81 3.5.1.81] Full crystallographic information is available from [http:// | + | 1M7J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=ACT:'>ACT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/N-acyl-D-amino-acid_deacylase N-acyl-D-amino-acid deacylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.81 3.5.1.81] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M7J OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: N-acyl-D-amino-acid deacylase]] | [[Category: N-acyl-D-amino-acid deacylase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chen, S | + | [[Category: Chen, S J.]] |
| - | [[Category: Hsu, C | + | [[Category: Hsu, C S.]] |
| - | [[Category: Ko, T | + | [[Category: Ko, T P.]] |
| - | [[Category: Liaw, S | + | [[Category: Liaw, S H.]] |
| - | [[Category: Tsai, Y | + | [[Category: Tsai, Y C.]] |
| - | [[Category: Wang, A | + | [[Category: Wang, A H.J.]] |
[[Category: ACT]] | [[Category: ACT]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
| Line 25: | Line 25: | ||
[[Category: tin-barrel]] | [[Category: tin-barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:52:22 2008'' |
Revision as of 11:52, 21 February 2008
|
Crystal structure of D-aminoacylase defines a novel subset of amidohydrolases
Overview
D-Aminoacylase is an attractive candidate for commercial production of D-amino acids through its catalysis in the hydrolysis of N-acyl-D-amino acids. We report here the first D-aminoacylase crystal structure from A. faecalis at 1.5-A resolution. The protein comprises a small beta-barrel, and a catalytic (betaalpha)(8)-barrel with a 63-residue insertion. The enzyme structure shares significant similarity to the alpha/beta-barrel amidohydrolase superfamily, in which the beta-strands in both barrels superimpose well. Unexpectedly, the enzyme binds two zinc ions with widely different affinities, although only the tightly bound zinc ion is required for activity. One zinc ion is coordinated by Cys(96), His(220), and His(250), while the other is loosely chelated by His(67), His(69), and Cys(96). This is the first example of the metal ion coordination by a cysteine residue in the superfamily. Therefore, D-aminoacylase defines a novel subset and is a mononuclear zinc metalloenzyme but containing a binuclear active site. The preferred substrate was modeled into a hydrophobic pocket, revealing the substrate specificity and enzyme catalysis. The 63-residue insertion containing substrate-interacting residues may act as a gate controlling access to the active site, revealing that the substrate binding would induce a closed conformation to sequester the catalysis from solvent.
About this Structure
1M7J is a Single protein structure of sequence from Alcaligenes faecalis with and as ligands. Active as N-acyl-D-amino-acid deacylase, with EC number 3.5.1.81 Full crystallographic information is available from OCA.
Reference
Crystal structure of D-aminoacylase from Alcaligenes faecalis DA1. A novel subset of amidohydrolases and insights into the enzyme mechanism., Liaw SH, Chen SJ, Ko TP, Hsu CS, Chen CJ, Wang AH, Tsai YC, J Biol Chem. 2003 Feb 14;278(7):4957-62. Epub 2002 Nov 25. PMID:12454005
Page seeded by OCA on Thu Feb 21 13:52:22 2008
