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| | ==Crystal Structure of IscR bound to its promoter== | | ==Crystal Structure of IscR bound to its promoter== |
| - | <StructureSection load='4hf1' size='340' side='right' caption='[[4hf1]], [[Resolution|resolution]] 2.22Å' scene=''> | + | <StructureSection load='4hf1' size='340' side='right'caption='[[4hf1]], [[Resolution|resolution]] 2.22Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4hf1]] is a 4 chain structure with sequence from [http://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=4HF1 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4HF1 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4hf1]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [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=4HF1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HF1 FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4hf0|4hf0]], [[4hf2|4hf2]]</td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.222Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">iscR, yfhP, b2531, JW2515 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 Escherichia coli K-12])</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=4hf1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hf1 OCA], [https://pdbe.org/4hf1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hf1 RCSB], [https://www.ebi.ac.uk/pdbsum/4hf1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hf1 ProSAT]</span></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=4hf1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hf1 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4hf1 RCSB], [http://www.ebi.ac.uk/pdbsum/4hf1 PDBsum]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/ISCR_ECOLI ISCR_ECOLI]] Regulates the transcription of several operons and genes involved in the biogenesis of Fe-S clusters and Fe-S-containing proteins. Transcriptional repressor of the iscRSUA operon, which is involved in the assembly of Fe-S clusters into Fe-S proteins. In its apoform, under conditions of oxidative stress or iron deprivation, it activates the suf operon, which is a second operon involved in the assembly of Fe-S clusters. Represses its own transcription as well as that of toxin rnlA.<ref>PMID:11742080</ref> <ref>PMID:16824106</ref> <ref>PMID:20421606</ref> | + | [https://www.uniprot.org/uniprot/ISCR_ECOLI ISCR_ECOLI] Regulates the transcription of several operons and genes involved in the biogenesis of Fe-S clusters and Fe-S-containing proteins. Transcriptional repressor of the iscRSUA operon, which is involved in the assembly of Fe-S clusters into Fe-S proteins. In its apoform, under conditions of oxidative stress or iron deprivation, it activates the suf operon, which is a second operon involved in the assembly of Fe-S clusters. Represses its own transcription as well as that of toxin rnlA.<ref>PMID:11742080</ref> <ref>PMID:16824106</ref> <ref>PMID:20421606</ref> |
| - | <div style="background-color:#fffaf0;">
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| - | == Publication Abstract from PubMed ==
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| - | IscR from Escherichia coli is an unusual metalloregulator in that both apo and iron sulfur (Fe-S)-IscR regulate transcription and exhibit different DNA binding specificities. Here, we report structural and biochemical studies of IscR suggesting that remodeling of the protein-DNA interface upon Fe-S ligation broadens the DNA binding specificity of IscR from binding the type 2 motif only to both type 1 and type 2 motifs. Analysis of an apo-IscR variant with relaxed target-site discrimination identified a key residue in wild-type apo-IscR that, we propose, makes unfavorable interactions with a type 1 motif. Upon Fe-S binding, these interactions are apparently removed, thereby allowing holo-IscR to bind both type 1 and type 2 motifs. These data suggest a unique mechanism of ligand-mediated DNA site recognition, whereby metallocluster ligation relocates a protein-specificity determinant to expand DNA target-site selection, allowing a broader transcriptomic response by holo-IscR.
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| - | Studies of IscR reveal a unique mechanism for metal-dependent regulation of DNA binding specificity.,Rajagopalan S, Teter SJ, Zwart PH, Brennan RG, Phillips KJ, Kiley PJ Nat Struct Mol Biol. 2013 Jun;20(6):740-7. doi: 10.1038/nsmb.2568. Epub 2013 May , 5. PMID:23644595<ref>PMID:23644595</ref>
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| - | </div>
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| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Escherichia coli k-12]] | + | [[Category: Escherichia coli]] |
| - | [[Category: Phillips, K J]] | + | [[Category: Escherichia coli K-12]] |
| - | [[Category: Rajagopalan, S R]]
| + | [[Category: Large Structures]] |
| - | [[Category: Dna binding]]
| + | [[Category: Phillips KJ]] |
| - | [[Category: Iron-sulfur cluster]]
| + | [[Category: Rajagopalan SR]] |
| - | [[Category: Protein-dna complex]] | + | |
| - | [[Category: Redox sensor]] | + | |
| - | [[Category: Transcription-dna complex]] | + | |
| - | [[Category: Transcriptional regulator]]
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| - | [[Category: Whth]]
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| - | [[Category: Winged helix-turn-helix]]
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