1f5t: Difference between revisions

New page: left|200px<br /><applet load="1f5t" size="450" color="white" frame="true" align="right" spinBox="true" caption="1f5t, resolution 3.00Å" /> '''DIPHTHERIA TOX REPRE...
 
No edit summary
 
(16 intermediate revisions by the same user not shown)
Line 1: Line 1:
[[Image:1f5t.gif|left|200px]]<br /><applet load="1f5t" size="450" color="white" frame="true" align="right" spinBox="true"
caption="1f5t, resolution 3.00&Aring;" />
'''DIPHTHERIA TOX REPRESSOR (C102D MUTANT) COMPLEXED WITH NICKEL AND DTXR CONSENSUS BINDING SEQUENCE'''<br />


==Overview==
==DIPHTHERIA TOX REPRESSOR (C102D MUTANT) COMPLEXED WITH NICKEL AND DTXR CONSENSUS BINDING SEQUENCE==
The expression of diphtheria toxin is controlled by the diphtheria toxin, repressor (DtxR). Under conditions of high iron concentration, DtxR binds, the tox operator to inhibit transcription. To study how DNA binding, specificity is achieved by this repressor, we solved the crystal structure, of the nickel(II) activated DtxR(C102D) mutant complexed with a 43mer DNA, duplex containing the DtxR consensus binding sequence. Structural analysis, of this complex and comparison with a previously determined, DtxR(C102D)-Ni(II)-tox operator ternary complex revealed unusual van der, Waals interactions between Ser37/Pro39 of the repressor helix-turn-helix, (HTH) motif and the methyl groups of specific thymine bases in the, consensus binding sequence. Gel mobility shift assays utilizing, deoxyuridine modified duplex DNA probes proved the importance of these, interactions: the four methyl groups shown to interact with Ser37/Pro39 in, the crystal structure contribute a total of 3.4 kcal/mol to binding, energy. Thus, in addition to making base-specific hydrogen-bonding, interactions to the DNA through its Gln43 residue, DtxR also recognizes, methyl groups at certain positions in the DNA sequence with its Ser37 and, Pro39 side chains, to achieve binding specificity toward its cognate, operator sequences.
<StructureSection load='1f5t' size='340' side='right'caption='[[1f5t]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1f5t]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Corynebacterium_diphtheriae Corynebacterium diphtheriae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F5T OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1F5T 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]] 3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NI:NICKEL+(II)+ION'>NI</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=1f5t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1f5t OCA], [https://pdbe.org/1f5t PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1f5t RCSB], [https://www.ebi.ac.uk/pdbsum/1f5t PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1f5t ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DTXR_CORDI DTXR_CORDI] Iron-binding repressor of the dipheteria toxin gene expression. May serve as a global regulator of gene expression. Represses ripA under iron excess.
== 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/f5/1f5t_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=1f5t ConSurf].
<div style="clear:both"></div>


==About this Structure==
==See Also==
1F5T is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Corynebacterium_diphtheriae Corynebacterium diphtheriae] with NI as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1F5T OCA].
*[[Diphtheria toxin repressor|Diphtheria toxin repressor]]
 
__TOC__
==Reference==
</StructureSection>
Methyl groups of thymine bases are important for nucleic acid recognition by DtxR., Chen CS, White A, Love J, Murphy JR, Ringe D, Biochemistry. 2000 Aug 29;39(34):10397-407. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10956029 10956029]
[[Category: Corynebacterium diphtheriae]]
[[Category: Corynebacterium diphtheriae]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Chen, S.]]
[[Category: Chen S]]
[[Category: Love, J.]]
[[Category: Love J]]
[[Category: Murphy, J.R.]]
[[Category: Murphy JR]]
[[Category: Ringe, D.]]
[[Category: Ringe D]]
[[Category: White, A.]]
[[Category: White A]]
[[Category: NI]]
[[Category: diphtheria tox repressor]]
[[Category: dna-binding regulatory protein]]
[[Category: dna-protein complex]]
[[Category: helix-turn-helix motif]]
[[Category: iron-regulated repressor]]
[[Category: transcription regulator]]
 
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 14:38:27 2007''

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA