1q6d: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
==Crystal structure of Soybean Beta-Amylase Mutant (M51T) with Increased pH Optimum== | ==Crystal structure of Soybean Beta-Amylase Mutant (M51T) with Increased pH Optimum== | ||
<StructureSection load='1q6d' size='340' side='right' caption='[[1q6d]], [[Resolution|resolution]] 2.00Å' scene=''> | <StructureSection load='1q6d' size='340' side='right' caption='[[1q6d]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
| Line 6: | Line 7: | ||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1q6c|1q6c]], [[1q6e|1q6e]], [[1q6f|1q6f]], [[1q6g|1q6g]]</td></tr> | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1q6c|1q6c]], [[1q6e|1q6e]], [[1q6f|1q6f]], [[1q6g|1q6g]]</td></tr> | ||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-amylase Beta-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.2 3.2.1.2] </span></td></tr> | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-amylase Beta-amylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.2 3.2.1.2] </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=1q6d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1q6d OCA], [http://pdbe.org/1q6d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1q6d RCSB], [http://www.ebi.ac.uk/pdbsum/1q6d PDBsum]</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=1q6d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1q6d OCA], [http://pdbe.org/1q6d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1q6d RCSB], [http://www.ebi.ac.uk/pdbsum/1q6d PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1q6d ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
| Line 12: | Line 13: | ||
Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q6/1q6d_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q6/1q6d_consurf.spt"</scriptWhenChecked> | ||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
| Line 27: | Line 28: | ||
</div> | </div> | ||
<div class="pdbe-citations 1q6d" style="background-color:#fffaf0;"></div> | <div class="pdbe-citations 1q6d" style="background-color:#fffaf0;"></div> | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 11:25, 24 February 2018
Crystal structure of Soybean Beta-Amylase Mutant (M51T) with Increased pH OptimumCrystal structure of Soybean Beta-Amylase Mutant (M51T) with Increased pH Optimum
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedComparison of the architecture around the active site of soybean beta-amylase and Bacillus cereus beta-amylase showed that the hydrogen bond networks (Glu380-(Lys295-Met51) and Glu380-Asn340-Glu178) in soybean beta-amylase around the base catalytic residue, Glu380, seem to contribute to the lower pH optimum of soybean beta-amylase. To convert the pH optimum of soybean beta-amylase (pH 5.4) to that of the bacterial type enzyme (pH 6.7), three mutants of soybean beta-amylase, M51T, E178Y, and N340T, were constructed such that the hydrogen bond networks were removed by site-directed mutagenesis. The kinetic analysis showed that the pH optimum of all mutants shifted dramatically to a neutral pH (range, from 5.4 to 6.0-6.6). The Km values of the mutants were almost the same as that of soybean beta-amylase except in the case of M51T, while the Vmax values of all mutants were low compared with that of soybean beta-amylase. The crystal structure analysis of the wild type-maltose and mutant-maltose complexes showed that the direct hydrogen bond between Glu380 and Asn340 was completely disrupted in the mutants M51T, E178Y, and N340T. In the case of M51T, the hydrogen bond between Glu380 and Lys295 was also disrupted. These results indicated that the reduced pKa value of Glu380 is stabilized by the hydrogen bond network and is responsible for the lower pH optimum of soybean beta-amylase compared with that of the bacterial beta-amylase. Structural and enzymatic analysis of soybean beta-amylase mutants with increased pH optimum.,Hirata A, Adachi M, Sekine A, Kang YN, Utsumi S, Mikami B J Biol Chem. 2004 Feb 20;279(8):7287-95. Epub 2003 Nov 24. PMID:14638688[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|
| ||||||||||||||||||||