1mxd
From Proteopedia
(New page: 200px<br /><applet load="1mxd" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mxd, resolution 2.0Å" /> '''Structure of a (Ca,Zn...) |
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| - | [[Image:1mxd.gif|left|200px]]<br /><applet load="1mxd" size=" | + | [[Image:1mxd.gif|left|200px]]<br /><applet load="1mxd" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mxd, resolution 2.0Å" /> | caption="1mxd, resolution 2.0Å" /> | ||
'''Structure of a (Ca,Zn)-dependent alpha-amylase from the hyperthermophilic archaeon Pyrococcus woesei'''<br /> | '''Structure of a (Ca,Zn)-dependent alpha-amylase from the hyperthermophilic archaeon Pyrococcus woesei'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the alpha-amylase from the hyperthermophilic | + | The crystal structure of the alpha-amylase from the hyperthermophilic archaeon Pyrococcus woesei was solved in the presence of three inhibitors: acarbose, Tris, and zinc. In the absence of exogenous metals, this alpha-amylase bound 1 and 4 molar eq of zinc and calcium, respectively. The structure reveals a novel, activating, two-metal (Ca,Zn)-binding site and a second inhibitory zinc-binding site that is found in the -1 sugar-binding pocket within the active site. The data resolve the apparent paradox between the zinc requirement for catalytic activity and its strong inhibitory effect when added in molar excess. They provide a rationale as to why this alpha-amylase, in contrast to commercially available alpha-amylases, does not require the addition of metal ions for full catalytic activity, suggesting it as an ideal target to maximize the efficiency of industrial processes like liquefaction of starch. |
==About this Structure== | ==About this Structure== | ||
| - | 1MXD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_woesei Pyrococcus woesei] with ACR, GLC, ZN, CA and ACT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] Full crystallographic information is available from [http:// | + | 1MXD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_woesei Pyrococcus woesei] with <scene name='pdbligand=ACR:'>ACR</scene>, <scene name='pdbligand=GLC:'>GLC</scene>, <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=ACT:'>ACT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alpha-amylase Alpha-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.1 3.2.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MXD OCA]. |
==Reference== | ==Reference== | ||
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[[Category: family 13 glycosyl hydrolase]] | [[Category: family 13 glycosyl hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:00:01 2008'' |
Revision as of 12:00, 21 February 2008
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Structure of a (Ca,Zn)-dependent alpha-amylase from the hyperthermophilic archaeon Pyrococcus woesei
Overview
The crystal structure of the alpha-amylase from the hyperthermophilic archaeon Pyrococcus woesei was solved in the presence of three inhibitors: acarbose, Tris, and zinc. In the absence of exogenous metals, this alpha-amylase bound 1 and 4 molar eq of zinc and calcium, respectively. The structure reveals a novel, activating, two-metal (Ca,Zn)-binding site and a second inhibitory zinc-binding site that is found in the -1 sugar-binding pocket within the active site. The data resolve the apparent paradox between the zinc requirement for catalytic activity and its strong inhibitory effect when added in molar excess. They provide a rationale as to why this alpha-amylase, in contrast to commercially available alpha-amylases, does not require the addition of metal ions for full catalytic activity, suggesting it as an ideal target to maximize the efficiency of industrial processes like liquefaction of starch.
About this Structure
1MXD is a Single protein structure of sequence from Pyrococcus woesei with , , , and as ligands. Active as Alpha-amylase, with EC number 3.2.1.1 Full crystallographic information is available from OCA.
Reference
Differential regulation of a hyperthermophilic alpha-amylase with a novel (Ca,Zn) two-metal center by zinc., Linden A, Mayans O, Meyer-Klaucke W, Antranikian G, Wilmanns M, J Biol Chem. 2003 Mar 14;278(11):9875-84. Epub 2002 Dec 12. PMID:12482867
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