1e7m
From Proteopedia
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|PDB= 1e7m |SIZE=350|CAPTION= <scene name='initialview01'>1e7m</scene>, resolution 2.54Å | |PDB= 1e7m |SIZE=350|CAPTION= <scene name='initialview01'>1e7m</scene>, resolution 2.54Å | ||
|SITE= <scene name='pdbsite=CA1:Ca+Binding+Site+For+Chain+A'>CA1</scene> | |SITE= <scene name='pdbsite=CA1:Ca+Binding+Site+For+Chain+A'>CA1</scene> | ||
| - | |LIGAND= <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | + | |LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Glucose-6-phosphate_1-dehydrogenase Glucose-6-phosphate 1-dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.49 1.1.1.49] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucose-6-phosphate_1-dehydrogenase Glucose-6-phosphate 1-dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.49 1.1.1.49] </span> |
|GENE= PLMZ/D177N ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1245 Leuconostoc mesenteroides]) | |GENE= PLMZ/D177N ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1245 Leuconostoc mesenteroides]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1e7m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1e7m OCA], [http://www.ebi.ac.uk/pdbsum/1e7m PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1e7m RCSB]</span> | ||
}} | }} | ||
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[[Category: Cosgrove, M S.]] | [[Category: Cosgrove, M S.]] | ||
[[Category: Gover, S.]] | [[Category: Gover, S.]] | ||
| - | [[Category: CA]] | ||
[[Category: glucose metabolism]] | [[Category: glucose metabolism]] | ||
[[Category: oxidoreductase (choh(d) - nad(p))]] | [[Category: oxidoreductase (choh(d) - nad(p))]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:56:52 2008'' |
Revision as of 16:56, 30 March 2008
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| , resolution 2.54Å | |||||||
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| Sites: | |||||||
| Ligands: | |||||||
| Gene: | PLMZ/D177N (Leuconostoc mesenteroides) | ||||||
| Activity: | Glucose-6-phosphate 1-dehydrogenase, with EC number 1.1.1.49 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ACTIVE SITE MUTANT (D177->N) OF GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM LEUCONOSTOC MESENTEROIDES
Overview
The role of Asp-177 in the His-Asp catalytic dyad of glucose 6-phosphate dehydrogenase from Leuconostoc mesenteroides has been investigated by a structural and functional characterization of the D177N mutant enzyme. Its three-dimensional structure has been determined by X-ray cryocrystallography in the presence of NAD(+) and in the presence of glucose 6-phosphate plus NADPH. The structure of a glucose 6-phosphate complex of a mutant (Q365C) with normal enzyme activity has also been determined and substrate binding compared. To understand the effect of Asp-177 on the ionization properties of the catalytic base His-240, the pH dependence of kinetic parameters has been determined for the D177N mutant and compared to that of the wild-type enzyme. The structures give details of glucose 6-phosphate binding and show that replacement of the Asp-177 of the catalytic dyad with asparagine does not affect the overall structure of glucose 6-phosphate dehydrogenase. Additionally, the evidence suggests that the productive tautomer of His-240 in the D177N mutant enzyme is stabilized by a hydrogen bond with Asn-177; hence, the mutation does not affect tautomer stabilization. We conclude, therefore, that the absence of a negatively charged aspartate at 177 accounts for the decrease in catalytic activity at pH 7.8. Structural analysis suggests that the pH dependence of the kinetic parameters of D177N glucose 6-phosphate dehydrogenase results from an ionized water molecule replacing the missing negative charge of the mutated Asp-177 at high pH. Glucose 6-phosphate binding orders and orients His-178 in the D177N-glucose 6-phosphate-NADPH ternary complex and appears to be necessary to form this water-binding site.
About this Structure
1E7M is a Single protein structure of sequence from Leuconostoc mesenteroides. Full crystallographic information is available from OCA.
Reference
An examination of the role of asp-177 in the His-Asp catalytic dyad of Leuconostoc mesenteroides glucose 6-phosphate dehydrogenase: X-ray structure and pH dependence of kinetic parameters of the D177N mutant enzyme., Cosgrove MS, Gover S, Naylor CE, Vandeputte-Rutten L, Adams MJ, Levy HR, Biochemistry. 2000 Dec 12;39(49):15002-11. PMID:11106478
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