1lq2
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1lq2.jpg|left|200px]] | + | [[Image:1lq2.jpg|left|200px]] |
| - | + | ||
| - | '''Crystal structure of barley beta-D-glucan glucohydrolase isoenzyme Exo1 in complex with gluco-phenylimidazole''' | + | {{Structure |
| + | |PDB= 1lq2 |SIZE=350|CAPTION= <scene name='initialview01'>1lq2</scene>, resolution 2.7Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=IDD:(5R,6R,7S,8S)-5-(HYDROXYMETHYL)-2-PHENYL-5,6,7,8-TETRAHYDROIMIDAZO[1,2-A]PYRIDINE-6,7,8-TRIOL'>IDD</scene> and <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Glucan_1,3-beta-glucosidase Glucan 1,3-beta-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.58 3.2.1.58] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''Crystal structure of barley beta-D-glucan glucohydrolase isoenzyme Exo1 in complex with gluco-phenylimidazole''' | ||
| + | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1LQ2 is a [ | + | 1LQ2 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LQ2 OCA]. |
==Reference== | ==Reference== | ||
| - | Three-dimensional structure of the barley beta-D-glucan glucohydrolase in complex with a transition state mimic., Hrmova M, De Gori R, Smith BJ, Vasella A, Varghese JN, Fincher GB, J Biol Chem. 2004 Feb 6;279(6):4970-80. Epub 2003 Nov 3. PMID:[http:// | + | Three-dimensional structure of the barley beta-D-glucan glucohydrolase in complex with a transition state mimic., Hrmova M, De Gori R, Smith BJ, Vasella A, Varghese JN, Fincher GB, J Biol Chem. 2004 Feb 6;279(6):4970-80. Epub 2003 Nov 3. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/14597633 14597633] |
[[Category: Glucan 1,3-beta-glucosidase]] | [[Category: Glucan 1,3-beta-glucosidase]] | ||
[[Category: Hordeum vulgare]] | [[Category: Hordeum vulgare]] | ||
| Line 26: | Line 35: | ||
[[Category: ligand-protein complex]] | [[Category: ligand-protein complex]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 12:33:52 2008'' |
Revision as of 10:33, 20 March 2008
| |||||||
| , resolution 2.7Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , and | ||||||
| Activity: | Glucan 1,3-beta-glucosidase, with EC number 3.2.1.58 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of barley beta-D-glucan glucohydrolase isoenzyme Exo1 in complex with gluco-phenylimidazole
Overview
Glucophenylimidazole (PheGlcIm), a tetrahydroimidazopyridine-type inhibitor and 4H3 conformer mimic of a glucoside, binds very tightly to a barley beta-d-glucan glucohydrolase, with a Ki constant of 2 x 10(-9) m and a DeltaG of 51 kJ mol(-1). PheGlcIm binds to the barley beta-d-glucan glucohydrolase approximately 2 x 10(5) times tighter than laminarin, which is the best non-synthetic ground-state substrate found so far for this enzyme, 10(6) times tighter than 4-nitrophenyl beta-d-glucopyranoside, and 2 x 10(7) tighter than glucose. The three-dimensional structure of the beta-d-glucan glucohydrolase with bound PheGlcIm indicates that the complex resembles a hypothetical transition state during the hydrolytic cycle, that the enzyme derives substrate binding energy from the "aglycone" portion of the ligand, and that it also reveals an anti-protonation trajectory for hydrolysis. Continuous electron densities at the 1.6 sigma level form between the three active site residues Asp95, His207, and Asp285, and the C6OH, C7OH, C8OH, and C9OH groups of PheGlcIm. These electron densities correspond to the most favorable interactions in the three-dimensional structure of the beta-d-glucan glucohydrolase-PheGlcIm complex and indicate atomic distances equal to or less than 2.55 A. The crystallographic data were corroborated with ab initio molecular orbital calculations. The data indicate that the 4E conformation of the glucose part of PheGlcIm is critical for tight binding and provide the first evidence for probable substrate distortion during catalysis by this enzyme.
About this Structure
1LQ2 is a Single protein structure of sequence from Hordeum vulgare. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of the barley beta-D-glucan glucohydrolase in complex with a transition state mimic., Hrmova M, De Gori R, Smith BJ, Vasella A, Varghese JN, Fincher GB, J Biol Chem. 2004 Feb 6;279(6):4970-80. Epub 2003 Nov 3. PMID:14597633
Page seeded by OCA on Thu Mar 20 12:33:52 2008
