1skb
From Proteopedia
(New page: 200px<br /><applet load="1skb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1skb, resolution 1.58Å" /> '''Crystallographic sna...) |
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| - | [[Image:1skb.gif|left|200px]]<br /><applet load="1skb" size=" | + | [[Image:1skb.gif|left|200px]]<br /><applet load="1skb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1skb, resolution 1.58Å" /> | caption="1skb, resolution 1.58Å" /> | ||
'''Crystallographic snapshots of Aspergillus fumigatus phytase revealing its enzymatic dynamics'''<br /> | '''Crystallographic snapshots of Aspergillus fumigatus phytase revealing its enzymatic dynamics'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Understanding of the atomic movements involved in an enzymatic reaction | + | Understanding of the atomic movements involved in an enzymatic reaction needs structural information on the active and inactive native enzyme molecules and on the enzyme-substrate, enzyme-intermediate, and enzyme-product(s) complexes. By using the X-ray crystallographic method, four crystal structures of Aspergillus fumigatus phytase were obtained at resolution higher than 1.7 A. The pH-dependent catalytic activity of A. fumigatus phytase was linked to three water molecules that may prevent the substrate from binding and thus block nucleophilic attack of the catalytic imidazole nitrogen. Comparison of various structures also identified the water molecule that attacks the phosphamide bond during the hydrolysis process, and established the hydrolysis pathway of the intermediate. Additionally, two reaction product phosphates were observed at the active site, suggesting a possible product release pathway after hydrolysis of the intermediate. These results can help explain the catalytic mechanism throughout the whole acid phosphatase family, as all key residues are conserved. |
==About this Structure== | ==About this Structure== | ||
| - | 1SKB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_fumigatus Aspergillus fumigatus] with NAG and NDG as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-phytase 3-phytase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.8 3.1.3.8] Full crystallographic information is available from [http:// | + | 1SKB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Aspergillus_fumigatus Aspergillus fumigatus] with <scene name='pdbligand=NAG:'>NAG</scene> and <scene name='pdbligand=NDG:'>NDG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-phytase 3-phytase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.8 3.1.3.8] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SKB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hao, Q.]] | [[Category: Hao, Q.]] | ||
[[Category: Huang, Q.]] | [[Category: Huang, Q.]] | ||
| - | [[Category: Lei, X | + | [[Category: Lei, X G.]] |
[[Category: Liu, Q.]] | [[Category: Liu, Q.]] | ||
[[Category: NAG]] | [[Category: NAG]] | ||
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[[Category: water structures]] | [[Category: water structures]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:02:21 2008'' |
Revision as of 13:02, 21 February 2008
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Crystallographic snapshots of Aspergillus fumigatus phytase revealing its enzymatic dynamics
Overview
Understanding of the atomic movements involved in an enzymatic reaction needs structural information on the active and inactive native enzyme molecules and on the enzyme-substrate, enzyme-intermediate, and enzyme-product(s) complexes. By using the X-ray crystallographic method, four crystal structures of Aspergillus fumigatus phytase were obtained at resolution higher than 1.7 A. The pH-dependent catalytic activity of A. fumigatus phytase was linked to three water molecules that may prevent the substrate from binding and thus block nucleophilic attack of the catalytic imidazole nitrogen. Comparison of various structures also identified the water molecule that attacks the phosphamide bond during the hydrolysis process, and established the hydrolysis pathway of the intermediate. Additionally, two reaction product phosphates were observed at the active site, suggesting a possible product release pathway after hydrolysis of the intermediate. These results can help explain the catalytic mechanism throughout the whole acid phosphatase family, as all key residues are conserved.
About this Structure
1SKB is a Single protein structure of sequence from Aspergillus fumigatus with and as ligands. Active as 3-phytase, with EC number 3.1.3.8 Full crystallographic information is available from OCA.
Reference
Crystallographic snapshots of Aspergillus fumigatus phytase, revealing its enzymatic dynamics., Liu Q, Huang Q, Lei XG, Hao Q, Structure. 2004 Sep;12(9):1575-83. PMID:15341723
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