1a72
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1a72.gif|left|200px]] | + | [[Image:1a72.gif|left|200px]] |
| - | + | ||
| - | '''AN ACTIVE-SITE DOUBLE MUTANT (PHE93->TRP, VAL203->ALA) OF HORSE LIVER ALCOHOL DEHYDROGENASE IN COMPLEX WITH THE ISOSTERIC NAD ANALOG CPAD''' | + | {{Structure |
| + | |PDB= 1a72 |SIZE=350|CAPTION= <scene name='initialview01'>1a72</scene>, resolution 2.6Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene> and <scene name='pdbligand=PAD:5-BETA-D-RIBOFURANOSYLPICOLINAMIDE ADENINE-DINUCLEOTIDE'>PAD</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= F93W V203ALADH ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9796 Equus caballus]) | ||
| + | }} | ||
| + | |||
| + | '''AN ACTIVE-SITE DOUBLE MUTANT (PHE93->TRP, VAL203->ALA) OF HORSE LIVER ALCOHOL DEHYDROGENASE IN COMPLEX WITH THE ISOSTERIC NAD ANALOG CPAD''' | ||
| + | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1A72 is a [ | + | 1A72 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=1A72 OCA]. |
==Reference== | ==Reference== | ||
| - | Active site modifications in a double mutant of liver alcohol dehydrogenase: structural studies of two enzyme-ligand complexes., Colby TD, Bahnson BJ, Chin JK, Klinman JP, Goldstein BM, Biochemistry. 1998 Jun 30;37(26):9295-304. PMID:[http:// | + | Active site modifications in a double mutant of liver alcohol dehydrogenase: structural studies of two enzyme-ligand complexes., Colby TD, Bahnson BJ, Chin JK, Klinman JP, Goldstein BM, Biochemistry. 1998 Jun 30;37(26):9295-304. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9649310 9649310] |
[[Category: Alcohol dehydrogenase]] | [[Category: Alcohol dehydrogenase]] | ||
[[Category: Equus caballus]] | [[Category: Equus caballus]] | ||
| Line 22: | Line 31: | ||
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: active site mutant]] | [[Category: active site mutant]] | ||
| - | [[Category: isosteric nad | + | [[Category: isosteric nad inhibitor]] |
[[Category: liver alcohol dehydrogenase]] | [[Category: liver alcohol dehydrogenase]] | ||
[[Category: oxidoreductase (nad(a)-choh(d))]] | [[Category: oxidoreductase (nad(a)-choh(d))]] | ||
| - | ''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 09:53:49 2008'' |
Revision as of 07:53, 20 March 2008
| |||||||
| , resolution 2.6Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | F93W V203ALADH (Equus caballus) | ||||||
| Activity: | Alcohol dehydrogenase, with EC number 1.1.1.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
AN ACTIVE-SITE DOUBLE MUTANT (PHE93->TRP, VAL203->ALA) OF HORSE LIVER ALCOHOL DEHYDROGENASE IN COMPLEX WITH THE ISOSTERIC NAD ANALOG CPAD
Overview
The oxidation of alcohol to aldehyde by horse liver alcohol dehydrogenase (LADH) requires the transfer of a hydride ion from the alcohol substrate to the cofactor nicotinamide adenine dinucleotide (NAD). A quantum mechanical tunneling contribution to this hydride transfer step has been demonstrated in a number of LADH mutants designed to enhance or diminish this effect [Bahnson, B. J., et al. (1997) Proc. Natl. Acad. Sci. U.S.A. 94, 12797-12802]. The active site double mutant Phe93 --> Trp/Val203 --> Ala shows a 75-fold reduction in catalytic efficiency relative to that of the native enzyme, and reduced tunneling relative to that of either single mutant. We present here two crystal structures of the double mutant: a 2.0 A complex with NAD and the substrate analogue trifluoroethanol and a 2.6 A complex with the isosteric NAD analogue CPAD and ethanol. Changes at the active site observed in both complexes are consistent with reduced activity and tunneling. The NAD-trifluoroethanol complex crystallizes in the closed conformation characteristic of the active enzyme. However, the NAD nicotinamide ring rotates away from the substrate, toward the space vacated by replacement of Val203 with the smaller alanine. Replacement of Phe93 with the larger tryptophan also produces unfavorable steric contacts with the nicotinamide carboxamide group, potentially destabilizing hydrogen bonds required to maintain the closed conformation. These contacts are relieved in the second complex by rotation of the CPAD pyridine ring into an unusual syn orientation. The resulting loss of the carboxamide hydrogen bonds produces an open conformation characteristic of the apoenzyme.
About this Structure
1A72 is a Single protein structure of sequence from Equus caballus. Full crystallographic information is available from OCA.
Reference
Active site modifications in a double mutant of liver alcohol dehydrogenase: structural studies of two enzyme-ligand complexes., Colby TD, Bahnson BJ, Chin JK, Klinman JP, Goldstein BM, Biochemistry. 1998 Jun 30;37(26):9295-304. PMID:9649310
Page seeded by OCA on Thu Mar 20 09:53:49 2008
