1mac: Difference between revisions
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== | ==CRYSTAL STRUCTURE AND SITE-DIRECTED MUTAGENESIS OF BACILLUS MACERANS ENDO-1,3-1,4-BETA-GLUCANASE== | ||
<StructureSection load='1mac' size='340' side='right'caption='[[1mac]], [[Resolution|resolution]] 2.30Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1mac]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Paenibacillus_macerans Paenibacillus macerans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MAC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1MAC 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]] 2.3Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=1mac FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1mac OCA], [https://pdbe.org/1mac PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1mac RCSB], [https://www.ebi.ac.uk/pdbsum/1mac PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1mac ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/GUB_PAEMA GUB_PAEMA] | |||
== 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/ma/1mac_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1mac ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
In beta-glucans those beta-1,4 glycosidic bonds which are adjacent to beta-1,3 bonds are cleaved by endo-1,3-1,4-beta-glucanases (beta-glucanases). Here, the relationship between structure and activity of the beta-glucanase of Bacillus macerans is studied by x-ray crystallography and site-directed mutagenesis of active site residues. Crystal structure analysis at 2.3-A resolution reveals a jelly-roll protein structure with a deep active site channel harboring the amino acid residues Trp101, Glu103, Asp105, and Glu107 as in the hybrid Bacillus beta-glucanase H(A16-M) (Keitel, T., Simon, O., Borriss, R., and Heinemann, U. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 5287-5291). Different mutant proteins with substitutions in these residues are generated by site-directed mutagenesis, isolated, and characterized. Compared with the wild-type enzyme their activity is reduced to less than 1%. Several mutants with isosteric substitutions in Glu103 and Glu107 are completely inactive, suggesting a direct role of these residues in glycosyl bond hydrolysis. The kinetic properties of mutant beta-glucanases and the crystal structure of the wild-type enzyme are consistent with a mechanism where Glu103 and Glu107 are the catalytic amino acid residues responsible for cleavage of the beta-1,4 glycosidic bond within the substrate molecule. | In beta-glucans those beta-1,4 glycosidic bonds which are adjacent to beta-1,3 bonds are cleaved by endo-1,3-1,4-beta-glucanases (beta-glucanases). Here, the relationship between structure and activity of the beta-glucanase of Bacillus macerans is studied by x-ray crystallography and site-directed mutagenesis of active site residues. Crystal structure analysis at 2.3-A resolution reveals a jelly-roll protein structure with a deep active site channel harboring the amino acid residues Trp101, Glu103, Asp105, and Glu107 as in the hybrid Bacillus beta-glucanase H(A16-M) (Keitel, T., Simon, O., Borriss, R., and Heinemann, U. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 5287-5291). Different mutant proteins with substitutions in these residues are generated by site-directed mutagenesis, isolated, and characterized. Compared with the wild-type enzyme their activity is reduced to less than 1%. Several mutants with isosteric substitutions in Glu103 and Glu107 are completely inactive, suggesting a direct role of these residues in glycosyl bond hydrolysis. The kinetic properties of mutant beta-glucanases and the crystal structure of the wild-type enzyme are consistent with a mechanism where Glu103 and Glu107 are the catalytic amino acid residues responsible for cleavage of the beta-1,4 glycosidic bond within the substrate molecule. | ||
Crystal structure and site-directed mutagenesis of Bacillus macerans endo-1,3-1,4-beta-glucanase.,Hahn M, Olsen O, Politz O, Borriss R, Heinemann U J Biol Chem. 1995 Feb 17;270(7):3081-8. PMID:7852389<ref>PMID:7852389</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[Category: | <div class="pdbe-citations 1mac" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Glucanase 3D structures|Glucanase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Paenibacillus macerans]] | [[Category: Paenibacillus macerans]] | ||
[[Category: Hahn M]] | |||
[[Category: Hahn | [[Category: Heinemann U]] | ||
[[Category: Heinemann | |||
Latest revision as of 05:31, 5 June 2024
CRYSTAL STRUCTURE AND SITE-DIRECTED MUTAGENESIS OF BACILLUS MACERANS ENDO-1,3-1,4-BETA-GLUCANASE
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