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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/Ecoli Ecoli]. 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='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='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 ECOLI])</td></tr>
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| - | <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://pdbe.org/4hf1 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4hf1 RCSB], [http://www.ebi.ac.uk/pdbsum/4hf1 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4hf1 ProSAT]</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;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Ecoli]] | + | [[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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| Structural highlights
Function
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.[1] [2] [3]
Publication Abstract from PubMed
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.
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[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Schwartz CJ, Giel JL, Patschkowski T, Luther C, Ruzicka FJ, Beinert H, Kiley PJ. IscR, an Fe-S cluster-containing transcription factor, represses expression of Escherichia coli genes encoding Fe-S cluster assembly proteins. Proc Natl Acad Sci U S A. 2001 Dec 18;98(26):14895-900. Epub 2001 Dec 11. PMID:11742080 doi:10.1073/pnas.251550898
- ↑ Yeo WS, Lee JH, Lee KC, Roe JH. IscR acts as an activator in response to oxidative stress for the suf operon encoding Fe-S assembly proteins. Mol Microbiol. 2006 Jul;61(1):206-18. PMID:16824106 doi:10.1111/j.1365-2958.2006.05220.x
- ↑ Otsuka Y, Miki K, Koga M, Katayama N, Morimoto W, Takahashi Y, Yonesaki T. IscR regulates RNase LS activity by repressing rnlA transcription. Genetics. 2010 Jul;185(3):823-30. doi: 10.1534/genetics.110.114462. Epub 2010 Apr, 26. PMID:20421606 doi:10.1534/genetics.110.114462
- ↑ Rajagopalan S, Teter SJ, Zwart PH, Brennan RG, Phillips KJ, Kiley PJ. Studies of IscR reveal a unique mechanism for metal-dependent regulation of DNA binding specificity. Nat Struct Mol Biol. 2013 Jun;20(6):740-7. doi: 10.1038/nsmb.2568. Epub 2013 May , 5. PMID:23644595 doi:10.1038/nsmb.2568
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