View source for 3iaq


==E. coli (lacz) beta-galactosidase (E416V)==
<StructureSection load='3iaq' size='340' side='right'caption='[[3iaq]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3iaq]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3IAQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3IAQ 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BTB:2-[BIS-(2-HYDROXY-ETHYL)-AMINO]-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>BTB</scene>, <scene name='pdbligand=DMS:DIMETHYL+SULFOXIDE'>DMS</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=3iaq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3iaq OCA], [https://pdbe.org/3iaq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3iaq RCSB], [https://www.ebi.ac.uk/pdbsum/3iaq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3iaq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BGAL_ECOLI BGAL_ECOLI] 
== 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/ia/3iaq_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=3iaq ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Variants of beta-galactosidase with Valine and with Glutamine replacing Glutamate-416 did not have a Mg(2+) bound at the active site even at high Mg(2+) concentrations (200 mM). They had low catalytic activity and the pH profiles were very different from those of the native enzyme. In addition, substrates, substrate analogs, transition state analogs and galactose bound very poorly. However, the orientation and conformation of the Mg(2+) ligands (residues 416, 418, and 461) as well as the B-factors of these three side chains did not change significantly. The structures, conformations and B-factors of other active site residues were also essentially unchanged. These studies show that the active site Mg(2+) is not necessary for structure and is, therefore, mainly important for modulating the chemistry and mediating the interactions between the active site components.

Studies of Glu-416 Variants of beta-Galactosidase (E. coli) Show that the Active Site Mg(2+) is Not Important for Structure and Indicate that the Main Role of Mg (2+) is to Mediate Optimization of Active Site Chemistry.,Lo S, Dugdale ML, Jeerh N, Ku T, Roth NJ, Huber RE Protein J. 2009 Nov 21. PMID:19936901<ref>PMID:19936901</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3iaq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Galactosidase 3D structures|Galactosidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Dugdale ML]]
[[Category: Huber RE]]
[[Category: Jeerh N]]
[[Category: Ku T]]
[[Category: Lo S]]
[[Category: Roth NJ]]