Transcription Factor
| Accessions: | ECK120008346 (RegulonDB 7.5) |
| Names: | IscR, IscR DNA-binding transcriptional dual regulator |
| Organisms: | ECK12 |
| Libraries: | RegulonDB 7.5 1 1 Salgado H, Peralta-Gil M, Gama-Castro S, Santos-Zavaleta A, Muniz-Rascado L, Garcia-Sotelo JS, Weiss V, Solano-Lira H, Martinez-Flores I, Medina-Rivera A, Salgado-Osorio G, Alquicira-Hernandez S, Alquicira-Hernandez K, Lopez-Fuentes A, Porron-Sotelo L, Huerta AM, Bonavides-Martinez C, Balderas-Martinez YI, Pannier L, Olvera M, Labastida A, Jimenez-Jacinto V, Vega-Alvarado L, Del Moral-Chavez V, Hernandez-Alvarez A, Morett E, Collado-Vides J. RegulonDB v8.0: omics data sets, evolutionary conservation, regulatory phrases, cross-validated gold standards and more. Nucleic Acids Res. 2013 Jan 1;41(D1):D203-D213. [Pubmed] |
| Notes: | The transcription factor IscR, for Iron-sulfur cluster Regulator, is negatively autoregulated, and it contains an iron-sulfur cluster that could act as a sensor of iron-sulfur cluster assembly Schwartz CJ,2001; Giel JL,2006 This protein regulates the expression of the operons that encode components of a secondary pathway of iron-sulfur cluster assembly, iron-sulfur proteins, anaerobic respiration enzymes, and biofilm formation Tokumoto U,2001; Schwartz CJ,2001; Giel JL,2006; Lee KC,2008; Yeo WS,2006; Wu Y,2009IscR is a member of the Rrf2 family Nesbit AD,2009and carries a predicted N-terminal helix-turn-helix DNA-binding motif and three conserved cysteines in its C terminus; IscR is a dimer in solution Nesbit AD,2009 and it contains the [2Fe-2S]1+ cluster when purified under anaerobic conditions Schwartz CJ,2001Two types of DNA-binding sites have been described for IscR: type 1 and type 2. Both sites resemble 25-bp imperfect palindromes but differ in their sequence Giel JL,2006; Nesbit AD,2009 IscR requires the iron-sulfur cluster for its activity when bound to type 1 sites; PiscR contains two type 1 sites Giel JL,2006 Therefore, under conditions when Fe-S cluster assembly becomes rate limiting, levels of [2Fe-2S]-containing IscR may decrease due to a lower rate of its synthesis, thus relieving repression of the iscRSUA operon for the biogenesis of the iron-sulfur cluster Schwartz CJ,2001; Frazzon J,2001 In contrast, for the regulation of promoters containing type 2 sites, such as PsufA, the [2Fe-2S] cluster of IscR is dispensable Yeo WS,2006; Lee KC,2008IscR binds cooperatively to DNA, and four protomers bind to one palindromic site Nesbit AD,2009; Transcription related; repressor; activator; operon; 2 iron, 2 sulfur cluster binding; iron-sulfur cluster binding; metal ion binding; response to stress; regulation of transcription, DNA-dependent; sequence-specific DNA binding transcription factor activity; double-stranded DNA binding; DNA binding; transcription activator activity; transcription, DNA- dependent; transcription repressor activity |
| Length: | 163 |
| Pfam Domains: | 1-83 Transcriptional regulator |
| Sequence: (in bold interface residues) | 1 MRLTSKGRYAVTAMLDVALNSEAGPVPLADISERQGISLSYLEQLFSRLRKNGLVSSVRG 60 61 PGGGYLLGKDASSIAVGEVISAVDESVDATRCQGKGGCQGGDKCLTHALWRDLSDRLTGF 120 121 LNNITLGELVNNQEVLDVSGRQHTHDAPRTRTQDAIDVKLRA* |
| Interface Residues: | 28, 38, 39, 40, 41, 43, 44, 47, 48, 51, 59, 61, 62 |
| 3D-footprint Homologues: | 2xro_E, 1u8r_B, 4hf1_A, 4on0_B, 2isz_B, 6y42_B, 7b0c_A, 1xs9_A, 2heo_D |
| Binding Motifs: | IscR wAwmCCCwdswAAhdbrrKsrw |
| Binding Sites: | ECK120017137 ECK120020692 ECK120020694 ECK120020696 ECK120020698 ECK120020700 ECK120020702 ECK120020704 ECK120033121 ECK120033123 ECK125109307 |
| Publications: | 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. 98(26):14895-900 (2001). [Pubmed] Giel JL., Rodionov D., Liu M., Blattner FR., Kiley PJ. IscR-dependent gene expression links iron-sulphur cluster assembly to the control of O-regulated genes in Escherichia coli. Mol Microbiol. 60(4):1058-75 (2006). [Pubmed] Tokumoto U., Takahashi Y. Genetic analysis of the isc operon in Escherichia coli involved in the biogenesis of cellular iron-sulfur proteins. J Biochem (Tokyo). 130(1):63-71 (2001). [Pubmed] Lee KC., Yeo WS., Roe JH. Oxidant-responsive induction of the suf operon, encoding a Fe-S assembly system, through Fur and IscR in Escherichia coli. J Bacteriol. 190(24):8244-7 (2008). [Pubmed] 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. 61(1):206-18 (2006). [Pubmed] Wu Y., Outten FW. IscR controls iron-dependent biofilm formation in Escherichia coli by regulating type I fimbria expression. J Bacteriol. 191(4):1248-57 (2009). [Pubmed] Nesbit AD., Giel JL., Rose JC., Kiley PJ. Sequence-specific binding to a subset of IscR-regulated promoters does not require IscR Fe-S cluster ligation. J Mol Biol. 387(1):28-41 (2009). [Pubmed] Frazzon J., Dean DR. Feedback regulation of iron-sulfur cluster biosynthesis. Proc Natl Acad Sci U S A. 98(26):14751-3 (2001). [Pubmed] |
| Related annotations: | PaperBLAST |
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