3buq: Difference between revisions
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==Golgi alpha-mannosidase II D204A catalytic nucleophile mutant with bound mannose.== | |||
<StructureSection load='3buq' size='340' side='right'caption='[[3buq]], [[Resolution|resolution]] 2.01Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3buq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Drosophila_melanogaster Drosophila melanogaster]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BUQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3BUQ FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.01Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3buq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3buq OCA], [https://pdbe.org/3buq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3buq RCSB], [https://www.ebi.ac.uk/pdbsum/3buq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3buq ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/MAN2_DROME MAN2_DROME] Catalyzes the first committed step in the biosynthesis of complex N-glycans. It controls conversion of high mannose to complex N-glycans; the final hydrolytic step in the N-glycan maturation pathway (By similarity). | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/bu/3buq_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3buq ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Inhibition of Golgi alpha-mannosidase II (GMII), which acts late in the N-glycan processing pathway, provides a route to blocking cancer-induced changes in cell surface oligosaccharide structures. To probe the substrate requirements of GMII, oligosaccharides were synthesized that contained an alpha(1,3)- or alpha(1,6)-linked 1-thiomannoside. Surprisingly, these oligosaccharides were not observed in X-ray crystal structures of native Drosophila GMII (dGMII). However, a mutant enzyme in which the catalytic nucleophilic aspartate was changed to alanine (D204A) allowed visualization of soaked oligosaccharides and led to the identification of the binding site for the alpha(1,3)-linked mannoside of the natural substrate. These studies also indicate that the conformational change of the bound mannoside to a high-energy B 2,5 conformation is facilitated by steric hindrance from, and the formation of strong hydrogen bonds to, Asp204. The observation that 1-thio-linked mannosides are not well tolerated by the catalytic site of dGMII led to the synthesis of a pentasaccharide containing the alpha(1,6)-linked Man of the natural substrate and the beta(1,2)-linked GlcNAc moiety proposed to be accommodated by the extended binding site of the enzyme. A cocrystal structure of this compound with the D204A enzyme revealed the molecular interactions with the beta(1,2)-linked GlcNAc. The structure is consistent with the approximately 80-fold preference of dGMII for the cleavage of substrates containing a nonreducing beta(1,2)-linked GlcNAc. By contrast, the lysosomal mannosidase lacks an equivalent GlcNAc binding site and kinetic analysis indicates oligomannoside substrates without non-reducing-terminal GlcNAc modifications are preferred, suggesting that selective inhibitors for GMII could exploit the additional binding specificity of the GlcNAc binding site. | |||
Probing the Substrate Specificity of Golgi alpha-Mannosidase II by Use of Synthetic Oligosaccharides and a Catalytic Nucleophile Mutant.,Zhong W, Kuntz DA, Ember B, Singh H, Moremen KW, Rose DR, Boons GJ J Am Chem Soc. 2008 Jun 18;. PMID:18558690<ref>PMID:18558690</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3buq" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
*[[Mannosidase|Mannosidase]] | *[[Mannosidase 3D structures|Mannosidase 3D structures]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Drosophila melanogaster]] | [[Category: Drosophila melanogaster]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Kuntz | [[Category: Kuntz DA]] | ||
[[Category: Rose | [[Category: Rose DR]] | ||