View source for 1eyc


==STRUCTURE OF S. NUCLEASE STABILIZING QUINTUPLE MUTANT T41I/S59A/P117G/H124L/S128A==
<StructureSection load='1eyc' size='340' side='right'caption='[[1eyc]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1eyc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/"micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EYC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EYC FirstGlance]. <br>
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ey0|1ey0]], [[1ey4|1ey4]], [[1ey5|1ey5]], [[1ey6|1ey6]], [[1ey7|1ey7]], [[1ey8|1ey8]], [[1ey9|1ey9]], [[1eya|1eya]], [[1eyd|1eyd]], [[1ez6|1ez6]], [[1ez8|1ez8]]</div></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Micrococcal_nuclease Micrococcal nuclease], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.31.1 3.1.31.1] </span></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=1eyc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eyc OCA], [https://pdbe.org/1eyc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1eyc RCSB], [https://www.ebi.ac.uk/pdbsum/1eyc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1eyc ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/NUC_STAAU NUC_STAAU]] Enzyme that catalyzes the hydrolysis of both DNA and RNA at the 5' position of the phosphodiester bond. 
== 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/ey/1eyc_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=1eyc ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Seven hyper-stable multiple mutants have been constructed in staphylococcal nuclease by various combinations of eight different stabilizing single mutants. The stabilities of these multiple mutants determined by guanidine hydrochloride denaturation were 3.4 to 5.6 kcal/mol higher than that of the wild-type. Their thermal denaturation midpoint temperatures were 12.6 to 22.9 deg. C higher than that of the wild-type. These are among the greatest increases in protein stability and thermal denaturation midpoint temperature relative to the wild-type yet attained. There has been great interest in understanding how proteins found in thermophilic organisms are stabilized. One frequently cited theory is that the packing of hydrophobic side-chains is improved in the cores of proteins isolated from thermophiles when compared to proteins from mesophiles. The crystal structures of four single and five multiple stabilizing mutants of staphylococcal nuclease were solved to high resolution. No large overall structural change was found, with most changes localized around the sites of mutation. Rearrangements were observed in the packing of side-chains in the major hydrophobic core, although none of the mutations was in the core. It is surprising that detailed structural analysis showed that packing had improved, with the volume of the mutant protein's hydrophobic cores decreasing as protein stability increased. Further, the number of van der Waals interactions in the entire protein showed an experimentally significant increase correlated with increasing stability. These results indicate that optimization of packing follows as a natural consequence of increased protein thermostability and that good packing is not necessarily the proximate cause of high stability. Another popular theory is that thermostable proteins have more electrostatic and hydrogen bonding interactions and these are responsible for the high stabilities. The mutants here show that increased numbers of electrostatic and hydrogen bonding interactions are not obligatory for large increases in protein stability.

Increasing the thermostability of staphylococcal nuclease: implications for the origin of protein thermostability.,Chen J, Lu Z, Sakon J, Stites WE J Mol Biol. 2000 Oct 20;303(2):125-30. PMID:11023780<ref>PMID:11023780</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1eyc" style="background-color:#fffaf0;"></div>

==See Also==
*[[Staphylococcal nuclease 3D structures|Staphylococcal nuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Micrococcal nuclease]]
[[Category: Chen, J]]
[[Category: Lu, Z]]
[[Category: Sakon, J]]
[[Category: Stites, W E]]
[[Category: Hydrolase]]