2g8s
From Proteopedia
(New page: 200px<br /><applet load="2g8s" size="450" color="white" frame="true" align="right" spinBox="true" caption="2g8s, resolution 1.500Å" /> '''Crystal structure o...) |
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| - | [[Image:2g8s.gif|left|200px]]<br /><applet load="2g8s" size=" | + | [[Image:2g8s.gif|left|200px]]<br /><applet load="2g8s" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2g8s, resolution 1.500Å" /> | caption="2g8s, resolution 1.500Å" /> | ||
'''Crystal structure of the soluble Aldose sugar dehydrogenase (Asd) from Escherichia coli in the apo-form'''<br /> | '''Crystal structure of the soluble Aldose sugar dehydrogenase (Asd) from Escherichia coli in the apo-form'''<br /> | ||
==Overview== | ==Overview== | ||
| - | A water-soluble aldose sugar dehydrogenase (Asd) has been purified for the | + | A water-soluble aldose sugar dehydrogenase (Asd) has been purified for the first time from Escherichia coli. The enzyme is able to act upon a broad range of aldose sugars, encompassing hexoses, pentoses, disaccharides, and trisaccharides, and is able to oxidize glucose to gluconolactone with subsequent hydrolysis to gluconic acid. The enzyme shows the ability to bind pyrroloquinoline quinone (PQQ) in the presence of Ca2+ in a manner that is proportional to its catalytic activity. The x-ray structure has been determined in the apo-form and as the PQQ-bound active holoenzyme. The beta-propeller fold of this protein is conserved between E. coli Asd and Acinetobacter calcoaceticus soluble glucose dehydrogenase (sGdh), with major structural differences lying in loop and surface-exposed regions. Many of the residues involved in binding the cofactor are conserved between the two enzymes, but significant differences exist in residues likely to contact substrates. PQQ is bound in a large cleft in the protein surface and is uniquely solvent-accessible compared with other PQQ enzymes. The exposed and charged nature of the active site and the activity profile of this enzyme indicate possible factors that underlie a low affinity for glucose but generic broad substrate specificity for aldose sugars. These structural and catalytic properties of the enzymes have led us to propose that E. coli Asd provides a prototype structure for a new subgroup of PQQ-dependent soluble dehydrogenases that is distinct from the A. calcoaceticus sGdh subgroup. |
==About this Structure== | ==About this Structure== | ||
| - | 2G8S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CA, PO4 and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2G8S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=EDO:'>EDO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G8S OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Doel, J | + | [[Category: Doel, J J.]] |
[[Category: Oubrie, A.]] | [[Category: Oubrie, A.]] | ||
| - | [[Category: Richardson, D | + | [[Category: Richardson, D J.]] |
| - | [[Category: Southall, S | + | [[Category: Southall, S M.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: EDO]] | [[Category: EDO]] | ||
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[[Category: quinoprotein]] | [[Category: quinoprotein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:29:15 2008'' |
Revision as of 15:29, 21 February 2008
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Crystal structure of the soluble Aldose sugar dehydrogenase (Asd) from Escherichia coli in the apo-form
Overview
A water-soluble aldose sugar dehydrogenase (Asd) has been purified for the first time from Escherichia coli. The enzyme is able to act upon a broad range of aldose sugars, encompassing hexoses, pentoses, disaccharides, and trisaccharides, and is able to oxidize glucose to gluconolactone with subsequent hydrolysis to gluconic acid. The enzyme shows the ability to bind pyrroloquinoline quinone (PQQ) in the presence of Ca2+ in a manner that is proportional to its catalytic activity. The x-ray structure has been determined in the apo-form and as the PQQ-bound active holoenzyme. The beta-propeller fold of this protein is conserved between E. coli Asd and Acinetobacter calcoaceticus soluble glucose dehydrogenase (sGdh), with major structural differences lying in loop and surface-exposed regions. Many of the residues involved in binding the cofactor are conserved between the two enzymes, but significant differences exist in residues likely to contact substrates. PQQ is bound in a large cleft in the protein surface and is uniquely solvent-accessible compared with other PQQ enzymes. The exposed and charged nature of the active site and the activity profile of this enzyme indicate possible factors that underlie a low affinity for glucose but generic broad substrate specificity for aldose sugars. These structural and catalytic properties of the enzymes have led us to propose that E. coli Asd provides a prototype structure for a new subgroup of PQQ-dependent soluble dehydrogenases that is distinct from the A. calcoaceticus sGdh subgroup.
About this Structure
2G8S is a Single protein structure of sequence from Escherichia coli with , and as ligands. Full crystallographic information is available from OCA.
Reference
Soluble aldose sugar dehydrogenase from Escherichia coli: a highly exposed active site conferring broad substrate specificity., Southall SM, Doel JJ, Richardson DJ, Oubrie A, J Biol Chem. 2006 Oct 13;281(41):30650-9. Epub 2006 Jul 24. PMID:16864586
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