1e77
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1e77.gif|left|200px]]<br /><applet load="1e77" size=" | + | [[Image:1e77.gif|left|200px]]<br /><applet load="1e77" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1e77, resolution 2.69Å" /> | caption="1e77, resolution 2.69Å" /> | ||
'''COMPLEX OF ACTIVE MUTANT (Q365->C) OF GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM LEUCONOSTOC MESENTEROIDES WITH SUBSTRATE'''<br /> | '''COMPLEX OF ACTIVE MUTANT (Q365->C) OF GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM LEUCONOSTOC MESENTEROIDES WITH SUBSTRATE'''<br /> | ||
| Line 7: | Line 7: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1E77 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Leuconostoc_mesenteroides Leuconostoc mesenteroides] with BG6 and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Known structural/functional Sites: <scene name='pdbsite=BG6:Bg6 Binding Site For Chain A'>BG6</scene> and <scene name='pdbsite=CA1:Ca Binding Site For Chain A'>CA1</scene>. Full crystallographic information is available from [http:// | + | 1E77 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Leuconostoc_mesenteroides Leuconostoc mesenteroides] with <scene name='pdbligand=BG6:'>BG6</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Known structural/functional Sites: <scene name='pdbsite=BG6:Bg6+Binding+Site+For+Chain+A'>BG6</scene> and <scene name='pdbsite=CA1:Ca+Binding+Site+For+Chain+A'>CA1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E77 OCA]. |
==Reference== | ==Reference== | ||
| Line 22: | Line 22: | ||
[[Category: oxidoreductase (choh(d) - nad(p))]] | [[Category: oxidoreductase (choh(d) - nad(p))]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:37:53 2008'' |
Revision as of 07:37, 3 February 2008
|
COMPLEX OF ACTIVE MUTANT (Q365->C) OF GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM LEUCONOSTOC MESENTEROIDES WITH SUBSTRATE
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
1E77 is a Single protein structure of sequence from Leuconostoc mesenteroides with and as ligands. Active as Glucose-6-phosphate 1-dehydrogenase, with EC number 1.1.1.49 Known structural/functional Sites: and . 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
Page seeded by OCA on Sun Feb 3 09:37:53 2008
