1e7m

<StructureSection load='1e7m' size='340' side='right' caption='[[1e7m]], [[Resolution|resolution]] 2.54&Aring;' scene=''>

<table><tr><td colspan='2'>[[1e7m]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E7M OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1E7M FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1dpg|1dpg]], [[1e77|1e77]], [[2dpg|2dpg]], [[1e7y|1e7y]]</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucose-6-phosphate_dehydrogenase Glucose-6-phosphate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.49 1.1.1.49] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><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://pdbe.org/1e7m PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1e7m RCSB], [http://www.ebi.ac.uk/pdbsum/1e7m PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1e7m ProSAT]</span></td></tr>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/e7/1e7m_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

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.

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<ref>PMID:11106478</ref>

 

[[Category: Glucose-6-phosphate dehydrogenase]]

[[Category: Adams, M J]]

[[Category: Cosgrove, M S]]

[[Category: Gover, S]]

[[Category: Glucose metabolism]]

[[Category: Oxidoreductase]]