View source for 1bi0


==STRUCTURE OF APO-AND HOLO-DIPHTHERIA TOXIN REPRESSOR==
<StructureSection load='1bi0' size='340' side='right'caption='[[1bi0]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1bi0]] is a 1 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=1BI0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BI0 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CSS:S-MERCAPTOCYSTEINE'>CSS</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=1bi0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bi0 OCA], [https://pdbe.org/1bi0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1bi0 RCSB], [https://www.ebi.ac.uk/pdbsum/1bi0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1bi0 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/bi/1bi0_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1bi0 ConSurf].
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== Publication Abstract from PubMed ==
The diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae is a divalent metal-activated repressor of chromosomal genes that encode proteins responsible for siderophore-mediated iron uptake and also of the gene of certain corynebacteriophages that encodes diphtheria toxin. DtxR consists of two 25.3-kDa three-domain subunits and is a member of a family of related repressor proteins in several Gram-positive bacterial species, some of which are important human pathogens. In this paper, we report on the first high resolution crystal structures of apo-DtxR in two related space groups. In addition, crystal structures of Zn-DtxR were determined in the same two space groups. The resolutions of the structures range from 2.2 to 2.4 A. The four refined models of the apo- and the holo-repressor exhibit quite similar metal binding centers, which do, however, show higher thermal motion in the apo-structures. All four structures reported differ from each other in one important aspect. The N-terminal DNA-binding domain and the last 20 residues of the dimerization domain of each subunit move significantly with respect to the core of the DtxR dimer, which consists of residues 74-120 from both subunits. These results provide the first indication of a conformational change that may occur upon binding of the holo-repressor to DNA.

Motion of the DNA-binding domain with respect to the core of the diphtheria toxin repressor (DtxR) revealed in the crystal structures of apo- and holo-DtxR.,Pohl E, Holmes RK, Hol WG J Biol Chem. 1998 Aug 28;273(35):22420-7. PMID:9712865<ref>PMID:9712865</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Diphtheria toxin repressor|Diphtheria toxin repressor]]
== References ==
<references/>
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</StructureSection>
[[Category: Corynebacterium diphtheriae]]
[[Category: Large Structures]]
[[Category: Hol WG]]
[[Category: Pohl E]]