1cjg: Difference between revisions

New page: left|200px<br /><applet load="1cjg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1cjg" /> '''NMR STRUCTURE OF LAC REPRESSOR HP62-DNA COMP...
 
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[[Image:1cjg.gif|left|200px]]<br /><applet load="1cjg" size="450" color="white" frame="true" align="right" spinBox="true"
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'''NMR STRUCTURE OF LAC REPRESSOR HP62-DNA COMPLEX'''<br />


==Overview==
==NMR STRUCTURE OF LAC REPRESSOR HP62-DNA COMPLEX==
BACKGROUND: Lactose repressor protein (Lac) controls the expression of the, lactose metabolic genes in Escherichia coli by binding to an operator, sequence in the promoter of the lac operon. Binding of inducer molecules, to the Lac core domain induces changes in tertiary structure that are, propagated to the DNA-binding domain through the connecting hinge region, thereby reducing the affinity for the operator. Protein-protein and, protein-DNA interactions involving the hinge region play a crucial role in, the allosteric changes occurring upon induction, but have not, as yet, been analyzed in atomic detail. RESULTS: We have used nuclear magnetic, resonance (NMR) spectroscopy and restrained molecular dynamics (rMD) to, determine the structure of the Lac repressor DNA-binding domain (headpeice, 62; HP62) in complex with a symmetrized lac operator. Analysis of the, structures reveals specific interactions between Lac repressor and DNA, that were not found in previously investigated Lac repressor-DNA, complexes. Important differences with the previously reported structures, of the HP56-DNA complex were found in the loop following the, helix-turn-helix (HTH) motif. The protein-protein and protein-DNA, interactions involving the hinge region and the deformations in the DNA, structure could be delineated in atomic detail. The structures were also, used for comparison with the available crystallographic data on the Lac, and Pur repressor-DNA complexes. CONCLUSIONS: The structures of the, HP62-DNA complex provide the basis for a better understanding of the, specific recognition in the Lac repressor-operator complex. In addition, the structural features of the hinge region provide detailed insight into, the protein-protein and protein-DNA interactions responsible for the high, affinity of the repressor for operator DNA.
<StructureSection load='1cjg' size='340' side='right'caption='[[1cjg]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1cjg]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CJG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CJG FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=1cjg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cjg OCA], [https://pdbe.org/1cjg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cjg RCSB], [https://www.ebi.ac.uk/pdbsum/1cjg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cjg ProSAT]</span></td></tr>
</table>
== Function ==
[https://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/cj/1cjg_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=1cjg ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
BACKGROUND: Lactose repressor protein (Lac) controls the expression of the lactose metabolic genes in Escherichia coli by binding to an operator sequence in the promoter of the lac operon. Binding of inducer molecules to the Lac core domain induces changes in tertiary structure that are propagated to the DNA-binding domain through the connecting hinge region, thereby reducing the affinity for the operator. Protein-protein and protein-DNA interactions involving the hinge region play a crucial role in the allosteric changes occurring upon induction, but have not, as yet, been analyzed in atomic detail. RESULTS: We have used nuclear magnetic resonance (NMR) spectroscopy and restrained molecular dynamics (rMD) to determine the structure of the Lac repressor DNA-binding domain (headpeice 62; HP62) in complex with a symmetrized lac operator. Analysis of the structures reveals specific interactions between Lac repressor and DNA that were not found in previously investigated Lac repressor-DNA complexes. Important differences with the previously reported structures of the HP56-DNA complex were found in the loop following the helix-turn-helix (HTH) motif. The protein-protein and protein-DNA interactions involving the hinge region and the deformations in the DNA structure could be delineated in atomic detail. The structures were also used for comparison with the available crystallographic data on the Lac and Pur repressor-DNA complexes. CONCLUSIONS: The structures of the HP62-DNA complex provide the basis for a better understanding of the specific recognition in the Lac repressor-operator complex. In addition, the structural features of the hinge region provide detailed insight into the protein-protein and protein-DNA interactions responsible for the high affinity of the repressor for operator DNA.


==About this Structure==
The solution structure of Lac repressor headpiece 62 complexed to a symmetrical lac operator.,Spronk CA, Bonvin AM, Radha PK, Melacini G, Boelens R, Kaptein R Structure. 1999 Dec 15;7(12):1483-92. PMID:10647179<ref>PMID:10647179</ref>
1CJG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1CJG OCA].


==Reference==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
The solution structure of Lac repressor headpiece 62 complexed to a symmetrical lac operator., Spronk CA, Bonvin AM, Radha PK, Melacini G, Boelens R, Kaptein R, Structure. 1999 Dec 15;7(12):1483-92. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10647179 10647179]
</div>
<div class="pdbe-citations 1cjg" style="background-color:#fffaf0;"></div>
 
==See Also==
*[[Lac repressor|Lac repressor]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Boelens, R.]]
[[Category: Boelens R]]
[[Category: Bonvin, A.M.J.J.]]
[[Category: Bonvin AMJJ]]
[[Category: Kaptein, R.]]
[[Category: Kaptein R]]
[[Category: Melacini, G.]]
[[Category: Melacini G]]
[[Category: Radha, P.K.]]
[[Category: Radha PK]]
[[Category: Spronk, C.A.E.M.]]
[[Category: Spronk CAEM]]
[[Category: headpiece]]
[[Category: lac operator]]
[[Category: lac operon]]
[[Category: lac repressor]]
[[Category: transcription regulation]]
 
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