2hk0
From Proteopedia
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|PDB= 2hk0 |SIZE=350|CAPTION= <scene name='initialview01'>2hk0</scene>, resolution 2.000Å | |PDB= 2hk0 |SIZE=350|CAPTION= <scene name='initialview01'>2hk0</scene>, resolution 2.000Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[2hk1|2HK1]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hk0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hk0 OCA], [http://www.ebi.ac.uk/pdbsum/2hk0 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2hk0 RCSB]</span> | ||
}} | }} | ||
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[[Category: tim-barrel]] | [[Category: tim-barrel]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 03:31:24 2008'' |
Revision as of 00:31, 31 March 2008
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| , resolution 2.000Å | |||||||
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| Ligands: | |||||||
| Related: | 2HK1
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of D-psicose 3-epimerase (DPEase) in the absence of substrate
Overview
D-psicose, a rare sugar produced by the enzymatic reaction of D-tagatose 3-epimerase (DTEase), has been used extensively for the bioproduction of various rare carbohydrates. Recently characterized D-psicose 3-epimerase (DPEase) from Agrobacterium tumefaciens was found to belong to the DTEase family and to catalyze the interconversion of D-fructose and D-psicose by epimerizing the C-3 position, with marked efficiency for D-psicose. The crystal structures of DPEase and its complex with the true substrate D-fructose were determined; DPEase is a tetramer and each monomer belongs to a TIM-barrel fold. The active site in each subunit is distinct from that of other TIM-barrel enzymes, which use phosphorylated ligands as the substrate. It contains a metal ion with octahedral coordination to two water molecules and four residues that are absolutely conserved across the DTEase family. Upon binding of D-fructose, the substrate displaces water molecules in the active site, with a conformation mimicking the intermediate cis-enediolate. Subsequently, Trp112 and Pro113 in the beta4-alpha4 loop undergo significant structural changes, sealing off the active site. Structural evidence and site-directed mutagenesis of the putative catalytic residues suggest that the metal ion plays a pivotal role in catalysis by anchoring the bound D-fructose, and Glu150 and Glu244 carry out an epimerization reaction at the C-3 position.
About this Structure
2HK0 is a Single protein structure of sequence from Agrobacterium tumefaciens. Full crystallographic information is available from OCA.
Reference
Crystal structure of D-psicose 3-epimerase from Agrobacterium tumefaciens and its complex with true substrate D-fructose: a pivotal role of metal in catalysis, an active site for the non-phosphorylated substrate, and its conformational changes., Kim K, Kim HJ, Oh DK, Cha SS, Rhee S, J Mol Biol. 2006 Sep 1;361(5):920-31. Epub 2006 Jul 28. PMID:16876192
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