1ju9: Difference between revisions
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'''HORSE LIVER ALCOHOL DEHYDROGENASE VAL292SER MUTANT''' | {{Structure | ||
|PDB= 1ju9 |SIZE=350|CAPTION= <scene name='initialview01'>1ju9</scene>, resolution 2.00Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> and <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Alcohol_dehydrogenase Alcohol dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.1 1.1.1.1] | |||
|GENE= M64864 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9796 Equus caballus]) | |||
}} | |||
'''HORSE LIVER ALCOHOL DEHYDROGENASE VAL292SER MUTANT''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1JU9 is a [ | 1JU9 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Equus_caballus Equus caballus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JU9 OCA]. | ||
==Reference== | ==Reference== | ||
Contributions of valine-292 in the nicotinamide binding site of liver alcohol dehydrogenase and dynamics to catalysis., Rubach JK, Ramaswamy S, Plapp BV, Biochemistry. 2001 Oct 23;40(42):12686-94. PMID:[http:// | Contributions of valine-292 in the nicotinamide binding site of liver alcohol dehydrogenase and dynamics to catalysis., Rubach JK, Ramaswamy S, Plapp BV, Biochemistry. 2001 Oct 23;40(42):12686-94. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11601993 11601993] | ||
[[Category: Alcohol dehydrogenase]] | [[Category: Alcohol dehydrogenase]] | ||
[[Category: Equus caballus]] | [[Category: Equus caballus]] | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
''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 12:08:33 2008'' | ||
Revision as of 10:08, 20 March 2008
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| 1ju9, resolution 2.00Å | |||||||||||||
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| Ligands: | ZN and NAD | ||||||||||||
| Gene: | M64864 (Equus caballus) | ||||||||||||
| Activity: | Alcohol dehydrogenase, with EC number 1.1.1.1 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
HORSE LIVER ALCOHOL DEHYDROGENASE VAL292SER MUTANT
Overview
The participation of Val-292 in catalysis by alcohol dehydrogenase and the involvement of dynamics were investigated. Val-292 interacts with the nicotinamide ring of the bound coenzyme and may facilitate hydride transfer. The substitution of Val-292 with Ser (V292S) increases the dissociation constants for the coenzymes (NAD(+) by 50-fold, NADH by 75-fold) and the turnover numbers by 3-7-fold. The V292S enzyme crystallized in the presence of NAD(+) and 2,3,4,5,6-pentafluorobenzyl alcohol has an open conformation similar to the structure of the wild-type apo-enzyme, rather than the closed conformation observed for ternary complexes with wild-type enzyme. The V292S substitution perturbs the conformational equilibrium of the enzyme and decreases the kinetic complexity, which permits study of the hydride transfer step with steady-state kinetics. Eyring plots show that the DeltaH for the oxidation (V(1)) of the protio and deuterio benzyl alcohols is 13 kcal/mol and that the kinetic isotope effect of 4.1 is essentially temperature-independent. Eyring plots for the catalytic efficiency for reduction of benzaldehyde (V(2)/K(p)) with NADH or NADD are distinctly convex, being temperature-dependent from 5 to 25 degrees C and temperature-independent from 25 to 50 degrees C; the kinetic isotope effect of 3.2 for V(2)/K(p) is essentially independent of the temperature. The temperature dependencies and isotope effects for V(1) and V(2)/K(p) are not adequately explained by semiclassical transition state theory and are better explained by hydride transfer occurring through vibrationally assisted tunneling.
About this Structure
1JU9 is a Single protein structure of sequence from Equus caballus. Full crystallographic information is available from OCA.
Reference
Contributions of valine-292 in the nicotinamide binding site of liver alcohol dehydrogenase and dynamics to catalysis., Rubach JK, Ramaswamy S, Plapp BV, Biochemistry. 2001 Oct 23;40(42):12686-94. PMID:11601993
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