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[[Image: | ==CRYSTAL STRUCTURE ANALYSIS OF THE TERNARY COMPLEX BETWEEN PSYCHROPHILIC ALPHA AMYLASE FROM PSEUDOALTEROMONAS HALOPLANCTIS IN COMPLEX WITH A HEPTA-SACCHARIDE AND A TRIS MOLECULE== | ||
<StructureSection load='1g94' size='340' side='right' caption='[[1g94]], [[Resolution|resolution]] 1.74Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1g94]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Pseudoalteromonas_haloplanktis Pseudoalteromonas haloplanktis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G94 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1G94 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene>, <scene name='pdbligand=DAF:4,6-DIDEOXY-4-{[(1S,5R,6S)-3-FORMYL-5,6-DIHYDROXY-4-OXOCYCLOHEX-2-EN-1-YL]AMINO}-ALPHA-D-XYLO-HEX-5-ENOPYRANOSE'>DAF</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1aqh|1aqh]], [[1aqm|1aqm]], [[1b0i|1b0i]]</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[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] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1g94 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g94 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1g94 RCSB], [http://www.ebi.ac.uk/pdbsum/1g94 PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/g9/1g94_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The psychrophilic Pseudoalteromonas haloplanctis alpha-amylase is shown to form ternary complexes with two alpha-amylase inhibitors present in the active site region, namely, a molecule of Tris and a trisaccharide inhibitor or heptasaccharide inhibitor, respectively. The crystal structures of these complexes have been determined by X-ray crystallography to 1.80 and 1.74 A resolution, respectively. In both cases, the prebound inhibitor Tris is expelled from the active site by the incoming oligosaccharide inhibitor substrate analogue, but stays linked to it, forming well-defined ternary complexes with the enzyme. These results illustrate competition in the crystalline state between two inhibitors, an oligosaccharide substrate analogue and a Tris molecule, bound at the same time in the active site region. Taken together, these structures show that the enzyme performs transglycosylation in the complex with the pseudotetrasaccharide acarbose (confirmed by a mutant structure), leading to a well-defined heptasaccharide, considered as a more potent inhibitor. Furthermore, the substrate-induced ordering of water molecules within a channel highlights a possible pathway used for hydrolysis of starch and related poly- and oligosaccharides. | |||
Crystallographic evidence of a transglycosylation reaction: ternary complexes of a psychrophilic alpha-amylase.,Aghajari N, Roth M, Haser R Biochemistry. 2002 Apr 2;41(13):4273-80. PMID:11914073<ref>PMID:11914073</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[ | *[[Amylase|Amylase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Alpha-amylase]] | [[Category: Alpha-amylase]] | ||
[[Category: Pseudoalteromonas haloplanktis]] | [[Category: Pseudoalteromonas haloplanktis]] | ||
Revision as of 14:40, 28 September 2014
CRYSTAL STRUCTURE ANALYSIS OF THE TERNARY COMPLEX BETWEEN PSYCHROPHILIC ALPHA AMYLASE FROM PSEUDOALTEROMONAS HALOPLANCTIS IN COMPLEX WITH A HEPTA-SACCHARIDE AND A TRIS MOLECULECRYSTAL STRUCTURE ANALYSIS OF THE TERNARY COMPLEX BETWEEN PSYCHROPHILIC ALPHA AMYLASE FROM PSEUDOALTEROMONAS HALOPLANCTIS IN COMPLEX WITH A HEPTA-SACCHARIDE AND A TRIS MOLECULE
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe psychrophilic Pseudoalteromonas haloplanctis alpha-amylase is shown to form ternary complexes with two alpha-amylase inhibitors present in the active site region, namely, a molecule of Tris and a trisaccharide inhibitor or heptasaccharide inhibitor, respectively. The crystal structures of these complexes have been determined by X-ray crystallography to 1.80 and 1.74 A resolution, respectively. In both cases, the prebound inhibitor Tris is expelled from the active site by the incoming oligosaccharide inhibitor substrate analogue, but stays linked to it, forming well-defined ternary complexes with the enzyme. These results illustrate competition in the crystalline state between two inhibitors, an oligosaccharide substrate analogue and a Tris molecule, bound at the same time in the active site region. Taken together, these structures show that the enzyme performs transglycosylation in the complex with the pseudotetrasaccharide acarbose (confirmed by a mutant structure), leading to a well-defined heptasaccharide, considered as a more potent inhibitor. Furthermore, the substrate-induced ordering of water molecules within a channel highlights a possible pathway used for hydrolysis of starch and related poly- and oligosaccharides. Crystallographic evidence of a transglycosylation reaction: ternary complexes of a psychrophilic alpha-amylase.,Aghajari N, Roth M, Haser R Biochemistry. 2002 Apr 2;41(13):4273-80. PMID:11914073[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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