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==Hypocrea jecorina Cel6A D221A mutant soaked with 4-Methylumbelliferyl- beta-D-cellobioside== | |||
<StructureSection load='4ax7' size='340' side='right'caption='[[4ax7]], [[Resolution|resolution]] 1.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4ax7]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Trichoderma_reesei Trichoderma reesei]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AX7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AX7 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]] 1.7Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=4MU:7-HYDROXY-4-METHYL-2H-CHROMEN-2-ONE'>4MU</scene>, <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PRD_900005:beta-cellobiose'>PRD_900005</scene>, <scene name='pdbligand=PRD_900011:beta-cellotetraose'>PRD_900011</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=4ax7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ax7 OCA], [https://pdbe.org/4ax7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ax7 RCSB], [https://www.ebi.ac.uk/pdbsum/4ax7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ax7 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/GUX2_HYPJE GUX2_HYPJE] The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Methylumbelliferyl-beta-cellobioside (MUF-G2) is a convenient fluorogenic substrate for certain beta-glycoside hydrolases (GH). However, hydrolysis of the aglycone is poor with GH family 6 enzymes (GH6), despite strong binding. Prediction of the orientation of the aglycone of MUF-G2 in the +1 subsite of Hypocrea jecorina Cel6A by automated docking suggested umbelliferyl modifications at C4 and C6 for improved recognition. Four modified umbelliferyl-beta-cellobiosides [6-chloro-4-methyl- (ClMUF); 6-chloro-4-trifluoromethyl- (ClF3MUF); 4-phenyl- (PhUF); 6-chloro-4-phenyl- (ClPhUF)] were synthesized and tested with GH6, GH7, GH9, GH5 and GH45 cellulases. Indeed the rate of aglycone release by H. jecorina Cel6A was 10-150 times higher than with MUF-G2, although it was still three orders of magnitude lower than with H. jecorina Cel7B. The 4-phenyl substitution drastically reduced the fluorescence intensity of the free aglycone, while ClMUF-G2 could be used for determination of k(cat) and K(M) for H. jecorina Cel6A and Thermobifida fusca Cel6A. Crystal structures of H. jecorina Cel6A D221A mutant soaked with the MUF-, ClMUF- and ClPhUF-beta-cellobioside substrates show that the modifications turned the umbelliferyl group 'upside down', with the glycosidic bond better positioned for protonation than with MUF-G2. DATABASE: Structural data have been submitted to the Protein Data Bank under accession numbers pdb 4AU0, 4AX7, 4AX6 STRUCTURED DIGITAL ABSTRACT: * http://mint.bio.uniroma2.it/mint/search/interaction.do?interactionAc=MINT-7260296 * Cel6A and Cel6A bind by x-ray crystallography (View Interaction: 1, 2). | |||
Rational design, synthesis, evaluation and enzyme-substrate structures of improved fluorogenic substrates for family 6 glycoside hydrolases.,Wu M, Nerinckx W, Piens K, Ishida T, Hansson H, Sandgren M, Stahlberg J FEBS J. 2013 Jan;280(1):184-98. doi: 10.1111/febs.12060. Epub 2012 Dec 7. PMID:23137336<ref>PMID:23137336</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4ax7" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
[[ | *[[Cellobiohydrolase 3D structures|Cellobiohydrolase 3D structures]] | ||
[[Category: | == References == | ||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Trichoderma reesei]] | [[Category: Trichoderma reesei]] | ||
[[Category: Hansson | [[Category: Hansson H]] | ||
[[Category: Ishida | [[Category: Ishida T]] | ||
[[Category: Nerinckx | [[Category: Nerinckx W]] | ||
[[Category: Piens | [[Category: Piens K]] | ||
[[Category: Sandgren | [[Category: Sandgren M]] | ||
[[Category: Stahlberg | [[Category: Stahlberg J]] | ||
[[Category: Wu | [[Category: Wu M]] | ||
Latest revision as of 14:37, 20 December 2023
Hypocrea jecorina Cel6A D221A mutant soaked with 4-Methylumbelliferyl- beta-D-cellobiosideHypocrea jecorina Cel6A D221A mutant soaked with 4-Methylumbelliferyl- beta-D-cellobioside
Structural highlights
FunctionGUX2_HYPJE The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose. Publication Abstract from PubMedMethylumbelliferyl-beta-cellobioside (MUF-G2) is a convenient fluorogenic substrate for certain beta-glycoside hydrolases (GH). However, hydrolysis of the aglycone is poor with GH family 6 enzymes (GH6), despite strong binding. Prediction of the orientation of the aglycone of MUF-G2 in the +1 subsite of Hypocrea jecorina Cel6A by automated docking suggested umbelliferyl modifications at C4 and C6 for improved recognition. Four modified umbelliferyl-beta-cellobiosides [6-chloro-4-methyl- (ClMUF); 6-chloro-4-trifluoromethyl- (ClF3MUF); 4-phenyl- (PhUF); 6-chloro-4-phenyl- (ClPhUF)] were synthesized and tested with GH6, GH7, GH9, GH5 and GH45 cellulases. Indeed the rate of aglycone release by H. jecorina Cel6A was 10-150 times higher than with MUF-G2, although it was still three orders of magnitude lower than with H. jecorina Cel7B. The 4-phenyl substitution drastically reduced the fluorescence intensity of the free aglycone, while ClMUF-G2 could be used for determination of k(cat) and K(M) for H. jecorina Cel6A and Thermobifida fusca Cel6A. Crystal structures of H. jecorina Cel6A D221A mutant soaked with the MUF-, ClMUF- and ClPhUF-beta-cellobioside substrates show that the modifications turned the umbelliferyl group 'upside down', with the glycosidic bond better positioned for protonation than with MUF-G2. DATABASE: Structural data have been submitted to the Protein Data Bank under accession numbers pdb 4AU0, 4AX7, 4AX6 STRUCTURED DIGITAL ABSTRACT: * http://mint.bio.uniroma2.it/mint/search/interaction.do?interactionAc=MINT-7260296 * Cel6A and Cel6A bind by x-ray crystallography (View Interaction: 1, 2). Rational design, synthesis, evaluation and enzyme-substrate structures of improved fluorogenic substrates for family 6 glycoside hydrolases.,Wu M, Nerinckx W, Piens K, Ishida T, Hansson H, Sandgren M, Stahlberg J FEBS J. 2013 Jan;280(1):184-98. doi: 10.1111/febs.12060. Epub 2012 Dec 7. PMID:23137336[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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