View source for 8yfz


==CRYSTAL STRUCTURE OF THE EST1 H274E MUTANT AT PH 4.2==
<StructureSection load='8yfz' size='340' side='right'caption='[[8yfz]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8yfz]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_shibatae Saccharolobus shibatae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8YFZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8YFZ 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]] 1.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BOG:B-OCTYLGLUCOSIDE'>BOG</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=8yfz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8yfz OCA], [https://pdbe.org/8yfz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8yfz RCSB], [https://www.ebi.ac.uk/pdbsum/8yfz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8yfz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q5NU42_9CREN Q5NU42_9CREN] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
SshEstI, a carboxylesterase from the thermoacidophilic archaeon Saccharolobus shibatae, is a member of the hormone-sensitive lipase family that displays slightly alkaliphilic activity with an optimum activity at pH 8.0. In this study, three distinct strategies were explored to confer acidophilic properties to SshEstI. The first strategy involved engineering the oxyanion hole by replacing Gly81 with serine or aspartic acid. The G81S mutant showed optimum activity at pH 7.0, whereas the aspartic acid mutant (G81D) rendered the enzyme slightly acidophilic with optimum activity observed at pH 6.0; however, k(cat) and k(cat)/K(m) values were reduced by these substitutions. The second strategy involved examining the effects of surfactant additives on the pH-activity profiles of SshEstI. The results showed that cetyltrimethylammonium bromide (CTAB) enhanced wild-type enzyme (WT) activity at acidic pH values. In the presence of 0.1 mM CTAB, G81S and G81D were acidophilic enzymes with optimum activity at pH 6.0 and 4.0, respectively, although their enzyme activities were low. The third strategy involved engineering the active site to resemble that of kumamolisin-As (kuma-As), an acidophilic peptidase of the sedolisin family. The catalytic triad of kuma-As was exchanged into SshEstI using site-directed mutagenesis. X-ray crystallographic analysis of the mutants (H274D and H274E) revealed that the potential hydrogen donor-acceptor distances around the active site of WT were fully maintained in these mutants. However, these mutants were inactive at pH 4-8.

Lowering pH optimum of activity of SshEstI, a slightly alkaliphilic archaeal esterase of the hormone-sensitive lipase family.,Ohara K, Oshima Y, Unno H, Nagano S, Kusunoki M, Takahashi S, Waki T, Yamashita S, Nakayama T J Biosci Bioeng. 2024 Jun 24:S1389-1723(24)00158-0. doi: , 10.1016/j.jbiosc.2024.05.010. PMID:38918133<ref>PMID:38918133</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8yfz" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharolobus shibatae]]
[[Category: Kusunoki M]]
[[Category: Nakayama T]]
[[Category: Nishino T]]
[[Category: Oshima Y]]
[[Category: Unno H]]