1bli
From Proteopedia
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| - | [[Image:1bli.gif|left|200px]]<br /><applet load="1bli" size=" | + | [[Image:1bli.gif|left|200px]]<br /><applet load="1bli" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bli, resolution 1.90Å" /> | caption="1bli, resolution 1.90Å" /> | ||
'''BACILLUS LICHENIFORMIS ALPHA-AMYLASE'''<br /> | '''BACILLUS LICHENIFORMIS ALPHA-AMYLASE'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1BLI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] with CA and NA 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] Known structural/functional Sites: <scene name='pdbsite=CA1:Ca Binding Site. This Ca Binding Site Is Conserved In Al ...'>CA1</scene>, <scene name='pdbsite=CA2:Ca Binding Site. This Ca Binding Site Is Not Conserved I ...'>CA2</scene>, <scene name='pdbsite=CA3:Ca Binding Site. This Ca Binding Site Located In The Int ...'>CA3</scene>, <scene name='pdbsite=CS:Catalytic Site'>CS</scene> and <scene name='pdbsite=NA1:Na Binding Site. This Is The First Na Binding Site Obser ...'>NA1</scene>. Full crystallographic information is available from [http:// | + | 1BLI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=NA:'>NA</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] Known structural/functional Sites: <scene name='pdbsite=CA1:Ca+Binding+Site.+This+Ca+Binding+Site+Is+Conserved+In+Al+...'>CA1</scene>, <scene name='pdbsite=CA2:Ca+Binding+Site.+This+Ca+Binding+Site+Is+Not+Conserved+I+...'>CA2</scene>, <scene name='pdbsite=CA3:Ca+Binding+Site.+This+Ca+Binding+Site+Located+In+The+Int+...'>CA3</scene>, <scene name='pdbsite=CS:Catalytic+Site'>CS</scene> and <scene name='pdbsite=NA1:Na+Binding+Site.+This+Is+The+First+Na+Binding+Site+Obser+...'>NA1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BLI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: thermostability]] | [[Category: thermostability]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:33:18 2008'' |
Revision as of 07:33, 3 February 2008
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BACILLUS LICHENIFORMIS ALPHA-AMYLASE
Overview
BACKGROUND: The structural basis as to how metals regulate the functional, state of a protein by altering or stabilizing its conformation has been, characterized in relatively few cases because the metal-free form of the, protein is often partially disordered and unsuitable for crystallographic, analysis. This is not the case, however, for Bacillus licheniformis, alpha-amylase (BLA) for which the structure of the metal-free form is, available. BLA is a hyperthermostable enzyme which is widely used in, biotechnology, for example in the breakdown of starch or as a component of, detergents. The determination of the structure of BLA in the, metal-containing form, together with comparisons to the apo enzyme, will, help us to understand the way in which metal ions can regulate enzyme, activity. RESULTS: We report here the crystal structure of native, metal-containing BLA. The structure shows that the calcium-binding site, which is conserved in all alpha-amylases forms part of an unprecedented, linear triadic metal array, with two calcium ions flanking a central, sodium ion. A region around the metal triad comprising 21 residues, exhibits a conformational change involving a helix unwinding and a, disorder-->order transition compared to the structure of metal-free BLA., Another calcium ion, not previously observed in alpha-amylases, is located, at the interface between domains A and C. CONCLUSIONS: We present a, structural description of a major conformational rearrangement mediated by, metal ions. The metal induced disorder-->order transition observed in BLA, leads to the formation of the extended substrate-binding site and explains, on a structural level the calcium dependency of alpha-amylases. Sequence, comparisons indicate that the unique Ca-Na-Ca metal triad and the, additional calcium ion located between domains A and C might be found, exclusively in bacterial alpha-amylases which show increased, thermostability. The information presented here may help in the rational, design of mutants with enhanced performance in biotechnological, applications.
About this Structure
1BLI is a Single protein structure of sequence from Bacillus licheniformis with and as ligands. Active as Alpha-amylase, with EC number 3.2.1.1 Known structural/functional Sites: , , , and . Full crystallographic information is available from OCA.
Reference
Activation of Bacillus licheniformis alpha-amylase through a disorder-->order transition of the substrate-binding site mediated by a calcium-sodium-calcium metal triad., Machius M, Declerck N, Huber R, Wiegand G, Structure. 1998 Mar 15;6(3):281-92. PMID:9551551
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