2g8s
From Proteopedia
Line 1: | Line 1: | ||
[[Image:2g8s.gif|left|200px]] | [[Image:2g8s.gif|left|200px]] | ||
- | + | <!-- | |
- | + | The line below this paragraph, containing "STRUCTURE_2g8s", creates the "Structure Box" on the page. | |
- | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
- | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
- | + | or leave the SCENE parameter empty for the default display. | |
- | + | --> | |
- | + | {{STRUCTURE_2g8s| PDB=2g8s | SCENE= }} | |
- | | | + | |
- | | | + | |
- | }} | + | |
'''Crystal structure of the soluble Aldose sugar dehydrogenase (Asd) from Escherichia coli in the apo-form''' | '''Crystal structure of the soluble Aldose sugar dehydrogenase (Asd) from Escherichia coli in the apo-form''' | ||
Line 30: | Line 27: | ||
[[Category: Southall, S M.]] | [[Category: Southall, S M.]] | ||
[[Category: 6 bladed beta-propellor]] | [[Category: 6 bladed beta-propellor]] | ||
- | [[Category: | + | [[Category: Quinoprotein]] |
- | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 04:49:45 2008'' | |
- | + | ||
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + |
Revision as of 01:49, 4 May 2008
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. 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 Page seeded by OCA on Sun May 4 04:49:45 2008