View source for 1jye


==Structure of a Dimeric Lac Repressor with C-terminal Deletion and K84L Substitution==
<StructureSection load='1jye' size='340' side='right' caption='[[1jye]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1jye]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JYE OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1JYE FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1jyf|1jyf]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">LacI ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</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=1jye FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1jye OCA], [http://pdbe.org/1jye PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1jye RCSB], [http://www.ebi.ac.uk/pdbsum/1jye PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1jye ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/LACI_ECOLI LACI_ECOLI]] Repressor of the lactose operon. Binds allolactose as an inducer. 
== 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/jy/1jye_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=1jye ConSurf].
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== Publication Abstract from PubMed ==
A single amino acid substitution, K84L, in the Escherichia coli lac repressor produces a protein that has substantially increased stability compared to wild-type. However, despite the increased stability, this altered tetrameric repressor has a tenfold reduced affinity for operator and greatly decreased rate-constants of inducer binding as well as a reduced phenotypic response to inducer in vivo. To understand the dramatic increase in stability and altered functional properties, we have determined the X-ray crystal structures of a dimeric repressor with and without the K84L substitution at resolutions of 1.7 and 3.0 A, respectively. In the wild-type dimer, K84-11, Lys84 forms electrostatic interactions at the monomer-monomer interface and is partially exposed to solvent. In the K84L-11 substituted protein there is reorientation of the N-subdomains, which allows the leucine to become deeply buried at the monomer-monomer interface. This reorientation of the N-subdomains, in turn, results in an alteration of hydrogen bonding, ion pairing, and van der Waals interactions at the monomer-monomer interface. The lysine residue at position 84 appears to exert its key effects by destabilizing the "optimal" conformation of the repressor, effectively loosening the dimer interface and allowing the repressor to adopt the conformations necessary to function as a molecular switch.

Structure of a variant of lac repressor with increased thermostability and decreased affinity for operator.,Bell CE, Barry J, Matthews KS, Lewis M J Mol Biol. 2001 Oct 12;313(1):99-109. PMID:11601849<ref>PMID:11601849</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 1jye" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus coli migula 1895]]
[[Category: Barry, J]]
[[Category: Bell, C E]]
[[Category: Lewis, M]]
[[Category: Matthews, K S]]
[[Category: Gene regulation]]
[[Category: Protein dna-binding]]
[[Category: Protein stability]]
[[Category: Transcription]]