Gene Symbol: lexA
Description: transcriptional repressor of SOS regulon
Alias: ECK4035, JW4003, exrA, spr, tsl, umuA
Species: Escherichia coli str. K-12 substr. MG1655
Products:     lexA

Top Publications

  1. Easton A, Kushner S. Transcription of the uvrD gene of Escherichia coli is controlled by the lexA repressor and by attenuation. Nucleic Acids Res. 1983;11:8625-40 pubmed
    ..Synthesis of messenger RNA in vitro from this promoter was inhibited by purified lexA protein...
  2. Giese K, Michalowski C, Little J. RecA-dependent cleavage of LexA dimers. J Mol Biol. 2008;377:148-61 pubmed publisher
    A critical step in the SOS response of Escherichia coli is the specific proteolytic cleavage of the LexA repressor...
  3. Little J. Mechanism of specific LexA cleavage: autodigestion and the role of RecA coprotease. Biochimie. 1991;73:411-21 pubmed
    Specific LexA cleavage can occur under two different conditions: RecA-mediated cleavage requires an activated form of RecA, while an intramolecular self-cleavage termed autodigestion proceeds spontaneously at high pH and does not involve ..
  4. Mrak P, Podlesek Z, van Putten J, Zgur Bertok D. Heterogeneity in expression of the Escherichia coli colicin K activity gene cka is controlled by the SOS system and stochastic factors. Mol Genet Genomics. 2007;277:391-401 pubmed
    ..Here, we report on the mechanism underlying this variable response. As colicin synthesis is regulated by the LexA protein, the central regulator of the SOS response, we focused on the role of LexA and the SOS system in the ..
  5. Pruteanu M, Baker T. Proteolysis in the SOS response and metal homeostasis in Escherichia coli. Res Microbiol. 2009;160:677-83 pubmed publisher
  6. Erill I, Escribano M, Campoy S, Barbe J. In silico analysis reveals substantial variability in the gene contents of the gamma proteobacteria LexA-regulon. Bioinformatics. 2003;19:2225-36 pubmed
    ..we make use of a consensus-building algorithm and comparative genomics to conduct an in-depth analysis of the LexA-regulon of gamma proteobacteria, and we use the inferred results to study the evolution of this regulatory network ..
  7. Maz n G, Erill I, Campoy S, Cort s P, Forano E, Barb J. Reconstruction of the evolutionary history of the LexA-binding sequence. Microbiology. 2004;150:3783-95 pubmed publisher
    In recent years, the recognition sequence of the SOS repressor LexA protein has been identified for several bacterial clades, such as the Gram-positive, green non-sulfur bacteria and Cyanobacteria phyla, or the 'Alphaproteobacteria', '..
  8. Fernandez de Henestrosa A, Ogi T, Aoyagi S, Chafin D, Hayes J, Ohmori H, et al. Identification of additional genes belonging to the LexA regulon in Escherichia coli. Mol Microbiol. 2000;35:1560-72 pubmed
    ..Expression of many of the genes in the SOS regulon are controlled by the LexA protein...
  9. Krishna S, Maslov S, Sneppen K. UV-induced mutagenesis in Escherichia coli SOS response: a quantitative model. PLoS Comput Biol. 2007;3:e41 pubmed
    ..In particular, we suggest that the recently observed second peak in the activity of promoters in the SOS regulon (Friedman et al., 2005, PLoS Biology 3(7): e238) is the result of positive feedback from Pol V to RecA filaments. ..

More Information


  1. Horii T, Ogawa T, Nakatani T, Hase T, Matsubara H, Ogawa H. Regulation of SOS functions: purification of E. coli LexA protein and determination of its specific site cleaved by the RecA protein. Cell. 1981;27:515-22 pubmed
    The LexA protein of Escherichia coli was purified to more than 96% purity from cells harboring a recombinant plasmid carrying the lexA gene with the lacZ promoter sequence...
  2. Wade J, Reppas N, Church G, Struhl K. Genomic analysis of LexA binding reveals the permissive nature of the Escherichia coli genome and identifies unconventional target sites. Genes Dev. 2005;19:2619-30 pubmed
    ..chromatin immunoprecipitation and high-density oligonucleotide microarrays to define the in vivo DNA targets of the LexA transcriptional repressor in Escherichia coli...
  3. Luo Y, Pfuetzner R, Mosimann S, Paetzel M, Frey E, Cherney M, et al. Crystal structure of LexA: a conformational switch for regulation of self-cleavage. Cell. 2001;106:585-94 pubmed
    b>LexA repressor undergoes a self-cleavage reaction. In vivo, this reaction requires an activated form of RecA, but it occurs spontaneously in vitro at high pH...
  4. McCool J, Long E, Petrosino J, Sandler H, Rosenberg S, Sandler S. Measurement of SOS expression in individual Escherichia coli K-12 cells using fluorescence microscopy. Mol Microbiol. 2004;53:1343-57 pubmed
    ..It is shown that the fluorescence in sulAp-gfp cells is regulated by RecA and LexA. This system was then used to distinguish between the two models for several mutants...
  5. Pennington J, Rosenberg S. Spontaneous DNA breakage in single living Escherichia coli cells. Nat Genet. 2007;39:797-802 pubmed
    ..Finally, FACS demonstrated two main cell fates after spontaneous DNA damage: viability with or without resumption of proliferation. ..
  6. Hashem V, Rosche W, Sinden R. Genetic recombination destabilizes (CTG)n.(CAG)n repeats in E. coli. Mutat Res. 2004;554:95-109 pubmed
    ..Using a genetic assay for repeat deletion in E. coli, the effect of mutations in the recA, recB, and lexA genes on the rate of deletion of (CTG)n.(CAG)n repeats of varying lengths were examined...
  7. Chen Z, Yang H, Pavletich N. Mechanism of homologous recombination from the RecA-ssDNA/dsDNA structures. Nature. 2008;453:489-4 pubmed publisher
    ..The underwound, stretched filament conformation probably evolved to destabilize the donor duplex, freeing the complementary strand for homology sampling...
  8. Little J, Mount D, Yanisch Perron C. Purified lexA protein is a repressor of the recA and lexA genes. Proc Natl Acad Sci U S A. 1981;78:4199-203 pubmed
    ..Previous evidence has suggested that the product of the lexA gene is involved in regulating the SOS response, perhaps as a repressor, and that it is sensitive to the recA ..
  9. Walker G. Mutagenesis and inducible responses to deoxyribonucleic acid damage in Escherichia coli. Microbiol Rev. 1984;48:60-93 pubmed
  10. Little J, Edmiston S, Pacelli L, Mount D. Cleavage of the Escherichia coli lexA protein by the recA protease. Proc Natl Acad Sci U S A. 1980;77:3225-9 pubmed
    The recA and lexA proteins of EScherichia coli are involved in a complex regulatory circuit that allows the expression of a diverse set of functions after DNA damage or inhibition of DNA replication...
  11. Yasuda T, Morimatsu K, Kato R, Usukura J, Takahashi M, Ohmori H. Physical interactions between DinI and RecA nucleoprotein filament for the regulation of SOS mutagenesis. EMBO J. 2001;20:1192-202 pubmed
    The Escherichia coli dinI gene is one of the LexA-regulated genes, which are induced upon DNA damage...
  12. Gillor O, Vriezen J, Riley M. The role of SOS boxes in enteric bacteriocin regulation. Microbiology. 2008;154:1783-92 pubmed publisher
    ..bacteriocin promoters reveals that over 75 % are regulated by dual, overlapping SOS boxes, which serve to bind two LexA repressor proteins...
  13. Mohana Borges R, Pacheco A, Sousa F, Foguel D, Almeida D, Silva J. LexA repressor forms stable dimers in solution. The role of specific dna in tightening protein-protein interactions. J Biol Chem. 2000;275:4708-12 pubmed
    Cooperativity in the interactions among proteins subunits and DNA is crucial for DNA recognition. LexA repressor was originally thought to bind DNA as a monomer, with cooperativity leading to tighter binding of the second monomer...
  14. Butala M, Zgur Bertok D, Busby S. The bacterial LexA transcriptional repressor. Cell Mol Life Sci. 2009;66:82-93 pubmed publisher
    Bacteria respond to DNA damage by mounting a coordinated cellular response, governed by the RecA and LexA proteins...
  15. Cox M. Regulation of bacterial RecA protein function. Crit Rev Biochem Mol Biol. 2007;42:41-63 pubmed
    ..Additional regulatory proteins may remain to be discovered. The elaborate regulatory pattern is likely to be reprised for RecA homologues in archaeans and eukaryotes. ..
  16. Chattopadhyaya R, Pal A. Improved model of a LexA repressor dimer bound to recA operator. J Biomol Struct Dyn. 2004;21:681-9 pubmed
    A complete three dimensional model for the LexA repressor dimer bound to the recA operator site consistent with relevant biochemical and biophysical data for the repressor was proposed from our laboratory when no crystal structure of LexA ..
  17. Sandler S, Samra H, Clark A. Differential suppression of priA2::kan phenotypes in Escherichia coli K-12 by mutations in priA, lexA, and dnaC. Genetics. 1996;143:5-13 pubmed
    ..We conclude that priA's primosome-assembly activity is essential for DNA repair and recombination and that the dnaC suppressor mutations allow these processes to occur in the absence of priA. ..
  18. Rangarajan S, Woodgate R, Goodman M. Replication restart in UV-irradiated Escherichia coli involving pols II, III, V, PriA, RecA and RecFOR proteins. Mol Microbiol. 2002;43:617-28 pubmed
    ..we have analysed the time dependence of replication restart in strains carrying a combination of mutations in lexA, recA, polB (pol II), umuDC (pol V), priA, dnaC, recF, recO or recR...
  19. Kornacker M, Remsburg B, Menzel R. Gene activation by the AraC protein can be inhibited by DNA looping between AraC and a LexA repressor that interacts with AraC: possible applications as a two-hybrid system. Mol Microbiol. 1998;30:615-24 pubmed
    The Escherichia coli activator and repressor proteins AraC and LexA bind DNA as homodimers...
  20. McCall J, Witkin E, Kogoma T, Roegner Maniscalco V. Constitutive expression of the SOS response in recA718 mutants of Escherichia coli requires amplification of RecA718 protein. J Bacteriol. 1987;169:728-34 pubmed
    In recA718 lexA+ strains of Escherichia coli, induction of the SOS response requires DNA damage...
  21. Moreau P, Fanica M, Devoret R. Cleavage of lambda repressor and induction of recA protein synthesis elicited by aflatoxin B1 metabolites in Escherichia coli. Carcinogenesis. 1980;1:837-48 pubmed
    ..Our results favour the idea that in aflatoxin B1-treated lysogens, DNA lesions activate RecA protein to cleave LexA protein, the repressor of the recA gene, and lambda repressor...
  22. Spek E, Wright T, Stitt M, Taghizadeh N, Tannenbaum S, Marinus M, et al. Recombinational repair is critical for survival of Escherichia coli exposed to nitric oxide. J Bacteriol. 2001;183:131-8 pubmed
    ..can induce. Furthermore, the importance of recombinational repair for cellular survival of NO(.) exposure reveals a potential susceptibility factor for invading microbes. ..
  23. Janion C. Inducible SOS response system of DNA repair and mutagenesis in Escherichia coli. Int J Biol Sci. 2008;4:338-44 pubmed
    ..but are not organized in an SOS system. This paper presents a brief up-to-date review describing the discovery of the SOS system, the physiology of SOS induction, methods for its determination, and the role of some SOS-induced genes. ..
  24. Aburatani S, Horimoto K. Elucidation of the relationships between LexA-regulated genes in the SOS response. Genome Inform. 2005;16:95-105 pubmed
    ..In this study, we analyzed the expression profiles of LexA-regulated genes after UV irradiation, to elucidate the genes related to the SOS response, which involves ..
  25. Schnarr M, Granger Schnarr M, Hurstel S, Pouyet J. The carboxy-terminal domain of the LexA repressor oligomerises essentially as the entire protein. FEBS Lett. 1988;234:56-60 pubmed
    The ability of the isolated carboxy-terminal domain of the LexA repressor of Escherichia coli to form dimers and tetramers has been investigated by equilibrium ultracentrifugation...
  26. D Ari R. The SOS system. Biochimie. 1985;67:343-7 pubmed
    ..The regulation of the SOS response involves a repressor, the LexA protein, and an inducer, the RecA protein...
  27. Belov O, Krasavin E, Parkhomenko A. Model of SOS-induced mutagenesis in bacteria Escherichia coli under ultraviolet irradiation. J Theor Biol. 2009;261:388-95 pubmed publisher
    ..We have also demonstrated the applicability of the developed model to the description of the mutagenesis in individual genes. As an example, an estimation of the mutation frequency in E. coli's lacI gene is performed. ..
  28. Brent R, Ptashne M. Mechanism of action of the lexA gene product. Proc Natl Acad Sci U S A. 1981;78:4204-8 pubmed
    Genetic experiments have suggested that the lexA gene product of Escherichia coli represses a number of genes involved in the response to DNA damage, including recA and lexA...
  29. Little J. Isolation of recombinant plasmids and phage carrying the lexA gene of Escherichia coli K-12. Gene. 1980;10:237-47 pubmed
    The lexA gene of Escherichia coli K-12 was cloned from the plasmid pLC44-14 into pBR322. Plasmids carrying lexA+ were selected by their ability to complement a recessive tsl mutation, which is believed to be a mutation in lexA...
  30. Mount D, Low K, Edmiston S. Dominant mutations (lex) in Escherichia coli K-12 which affect radiation sensitivity and frequency of ultraviolet lght-induced mutations. J Bacteriol. 1972;112:886-93 pubmed
    ..Stable lex(+)/lec(-) heterozygotes are found to have the mutant radiation-sensitive phenotype of haploid lex(-) strains. ..
  31. Hill T, Sharma B, Valjavec Gratian M, Smith J. sfi-independent filamentation in Escherichia coli Is lexA dependent and requires DNA damage for induction. J Bacteriol. 1997;179:1931-9 pubmed
    ..We report here that sfi-independent filamentation is suppressed by lexA(Ind-) mutations, suggesting that derepression of the LexA regulon is necessary for sfi-independent induction...
  32. Little J, Harper J. Identification of the lexA gene product of Escherichia coli K-12. Proc Natl Acad Sci U S A. 1979;76:6147-51 pubmed
    The Escherichia coli lexA gene encodes a product important in induction of the recA gene and the expression of various cellular functions, including mutagenesis and prophage induction...
  33. Rehrauer W, Lavery P, Palmer E, Singh R, Kowalczykowski S. Interaction of Escherichia coli RecA protein with LexA repressor. I. LexA repressor cleavage is competitive with binding of a secondary DNA molecule. J Biol Chem. 1996;271:23865-73 pubmed
    ..coli, RecA protein promotes the homologous pairing and exchange of DNA strands and the proteolytic cleavage of the LexA repressor, respectively...
  34. Drees J, Lusetti S, Chitteni Pattu S, Inman R, Cox M. A RecA filament capping mechanism for RecX protein. Mol Cell. 2004;15:789-98 pubmed
    ..RecX protein interacts directly with RecA protein, but appears to interact in a functionally significant manner only with RecA filaments bound to DNA. ..
  35. Clark A. recA operator mutations and their usefulness. Biochimie. 1982;64:669-75 pubmed
    ..Derepressed amounts of recA protein vary over a forty-fold range and correlate well with reduced affinities for lexA repressor of the mutant operators...
  36. Krueger J, Elledge S, Walker G. Isolation and characterization of Tn5 insertion mutations in the lexA gene of Escherichia coli. J Bacteriol. 1983;153:1368-78 pubmed
    ..Three mutants were obtained that contained Tn5 insertions genetically linked to the lexA gene and had properties that suggested the mutants were deficient in lexA expression...
  37. Al Mamun A, Humayun M. Spontaneous mutagenesis is elevated in protease-defective cells. Mol Microbiol. 2009;71:629-39 pubmed publisher
    ..These findings suggest that in normal cells, Clp-mediated proteolysis plays an important role in preventing gratuitous mutagenesis. ..
  38. Andersson S, Lagergren J. Motif Yggdrasil: sampling sequence motifs from a tree mixture model. J Comput Biol. 2007;14:682-97 pubmed
    ..a substantial increase in nucleotide level correlation coefficient both for synthetic data and 37 bacterial lexA genes...
  39. Hendricks E, Szerlong H, Hill T, Kuempel P. Cell division, guillotining of dimer chromosomes and SOS induction in resolution mutants (dif, xerC and xerD) of Escherichia coli. Mol Microbiol. 2000;36:973-81 pubmed
    ..However, pedigree analysis of cells in microcolonies demonstrated that lethal sectoring occurred as a result of limited growth and division of dead cells produced by guillotining. ..
  40. Butala M, Sonjak S, Kamen ek S, Hodo ek M, Browning D, gur Bertok D, et al. Double locking of an Escherichia coli promoter by two repressors prevents premature colicin expression and cell lysis. Mol Microbiol. 2012;86:129-39 pubmed publisher
    ..synthesis of Eschericha coli colicins is lethal to the producing cell and is repressed during normal growth by the LexA transcription factor, which is the master repressor of the SOS system for repair of DNA damage...
  41. Knegtel R, Fogh R, Ottleben G, Rüterjans H, Dumoulin P, Schnarr M, et al. A model for the LexA repressor DNA complex. Proteins. 1995;21:226-36 pubmed
    A structural model for the interaction of the LexA repressor DNA binding domain (DBD) with operator DNA is derived by means of Monte Carlo docking...
  42. Camas F, Blazquez J, Poyatos J. Autogenous and nonautogenous control of response in a genetic network. Proc Natl Acad Sci U S A. 2006;103:12718-23 pubmed
    ..We redesign the control of its master regulator, the protein LexA, so that it becomes nonautogenously controlled...
  43. Schneider D, Kaiser W, Stutz C, Holinski A, Mayans O, Babinger P. YbiB from Escherichia coli, the Defining Member of the Novel TrpD2 Family of Prokaryotic DNA-binding Proteins. J Biol Chem. 2015;290:19527-39 pubmed publisher
    ..The ybiB gene forms an operon with the DNA helicase gene dinG and is under LexA control, being induced by DNA-damaging agents...
  44. Delmas S, Matic I. Cellular response to horizontally transferred DNA in Escherichia coli is tuned by DNA repair systems. DNA Repair (Amst). 2005;4:221-9 pubmed
    ..We discuss the role of molecular mechanisms involved in the control of the recombination between diverged DNA sequences in the maintenance of genomic stability and genome evolution. ..
  45. Lamerichs R, Padilla A, Boelens R, Kaptein R, Ottleben G, Rüterjans H, et al. The amino-terminal domain of LexA repressor is alpha-helical but differs from canonical helix-turn-helix proteins: a two-dimensional 1H NMR study. Proc Natl Acad Sci U S A. 1989;86:6863-7 pubmed
    The amino-terminal DNA binding domain of LexA repressor consisting of 84 amino acid residues has been studied by two-dimensional 1H NMR. Sequence-specific 1H resonance assignments were made for the first 60 amino acid residues...
  46. Wade J, Struhl K. Association of RNA polymerase with transcribed regions in Escherichia coli. Proc Natl Acad Sci U S A. 2004;101:17777-82 pubmed
    ..with the promoter-proximal region of several operons, and this preference is particularly pronounced at the lexA-dinF promoter...
  47. Janky R, van Helden J. Evaluation of phylogenetic footprint discovery for predicting bacterial cis-regulatory elements and revealing their evolution. BMC Bioinformatics. 2008;9:37 pubmed publisher
    ..We further report a detailed analysis of 181 bacterial orthologs of the LexA repressor...
  48. Uhlin B, Volkert M, Clark A, Sancar A, Rupp W. Nucleotide sequence of a recA operator mutation. LexA/operator-repressor binding/inducible repair. Mol Gen Genet. 1982;185:251-4 pubmed
  49. Bridges B. Error-prone repair and translesion synthesis III: the activation of UmuD (or less is more). DNA Repair (Amst). 2005;4:1047-8, 1058-9 pubmed
    ..coli bacteria, RecA protein is activated by binding to single stranded DNA and cleaves its own gene repressor (LexA protein)...
  50. Lin L, Little J. Isolation and characterization of noncleavable (Ind-) mutants of the LexA repressor of Escherichia coli K-12. J Bacteriol. 1988;170:2163-73 pubmed
    The LexA repressor of Escherichia coli represses a set of genes that are expressed in the response to DNA damage...
  51. Drees J, Chitteni Pattu S, McCaslin D, Inman R, Cox M. Inhibition of RecA protein function by the RdgC protein from Escherichia coli. J Biol Chem. 2006;281:4708-17 pubmed
    ..RdgC inhibits RecA protein-promoted DNA strand exchange, ATPase activity, and RecA-dependent LexA cleavage...
  52. Khanin R, Vinciotti V, Wit E. Reconstructing repressor protein levels from expression of gene targets in Escherichia coli. Proc Natl Acad Sci U S A. 2006;103:18592-6 pubmed
    ..an example of an SOS repair system, and computationally infer the regulator activity of its master repressor, LexA. The reconstructed activity profile of LexA exhibits a behavior that is similar to the experimentally measured ..
  53. Aertsen A, Michiels C. Upstream of the SOS response: figure out the trigger. Trends Microbiol. 2006;14:421-3 pubmed
    ..We suggest that these endogenous triggers have been recruited by bacteria to enable adaptation to various types of stresses. ..
  54. Kelley W. Lex marks the spot: the virulent side of SOS and a closer look at the LexA regulon. Mol Microbiol. 2006;62:1228-38 pubmed
    The SOS response that responds to DNA damage induces many genes that are under LexA repression...
  55. Mardanov A, Ravin N. The antirepressor needed for induction of linear plasmid-prophage N15 belongs to the SOS regulon. J Bacteriol. 2007;189:6333-8 pubmed publisher
    ..b>LexA binds to and represses the promoter of antC...
  56. Li B, Smith P, Horvath D, Romesberg F, Justice S. SOS regulatory elements are essential for UPEC pathogenesis. Microbes Infect. 2010;12:662-8 pubmed publisher
    ..b>LexA and RecA coordinate various operons for repair of DNA damage due to exogenous and endogenous agents and are known ..
  57. Lanzov V, Bakhlanova I, Clark A. Conjugational hyperrecombination achieved by derepressing the LexA regulon, altering the properties of RecA protein and inactivating mismatch repair in Escherichia coli K-12. Genetics. 2003;163:1243-54 pubmed
    ..Using these conditions we showed a cumulative effect of various mutations on FRE. Constitutive SOS expression by lexA gene inactivation (lexA71::Tn5) and recA gene mutation (recA730) showed, respectively, approximately 4- and 7-fold ..
  58. Sousa F, Lima L, Pacheco A, Oliveira C, Torriani I, Almeida D, et al. Tetramerization of the LexA repressor in solution: implications for gene regulation of the E.coli SOS system at acidic pH. J Mol Biol. 2006;359:1059-74 pubmed
    Structural changes on LexA repressor promoted by acidic pH have been investigated. Intense protein aggregation occurred around pH 4.0 but was not detected at pH values lower than pH 3.5...
  59. Gudas L, Pardee A. Model for regulation of Escherichia coli DNA repair functions. Proc Natl Acad Sci U S A. 1975;72:2330-4 pubmed
    ..The model states tht: (1) The lex (or exrA in E. coli B) gene codes for a repressor...
  60. Sedgwick S, Goodwin P. Interspecies regulation of the SOS response by the E. coli lexA+ gene. Mutat Res. 1985;145:103-6 pubmed
    A plasmid-encoded E. coli lexA+ gene was introduced into 6 species of Enterobacteria. Ultraviolet light-sensitization occurred in all species except P. rettgeri, and 4 organisms showed reduced inducibility of RecA-like proteins...
  61. Brent R, Ptashne M. The lexA gene product represses its own promoter. Proc Natl Acad Sci U S A. 1980;77:1932-6 pubmed
    The products of the lexA and recA genes of Escherichia coli regulate the cellular response to DNA damage (the SOS response)...
  62. Lovett S, Clark A. Genetic analysis of regulation of the RecF pathway of recombination in Escherichia coli K-12. J Bacteriol. 1983;153:1471-8 pubmed
    ..the hypothesis that one or more genes of the RecF pathway of recombination other than recA are controlled by the lexA repressor...
  63. Morganroth P, Hanawalt P. Role of DNA replication and repair in thymineless death in Escherichia coli. J Bacteriol. 2006;188:5286-8 pubmed
    ..Hydroxyurea experiments and thymine starvation of lexA3 and uvrA DNA repair mutants rule out unbalanced growth, the SOS response, and nucleotide excision repair as explanations for TLD. ..
  64. Fogh R, Ottleben G, Rüterjans H, Schnarr M, Boelens R, Kaptein R. Solution structure of the LexA repressor DNA binding domain determined by 1H NMR spectroscopy. EMBO J. 1994;13:3936-44 pubmed
    The structure of the 84 residue DNA binding domain of the Escherichia coli LexA repressor has been determined from NMR data using distance geometry and restrained molecular dynamics...
  65. Ingmer H, Miller C, Cohen S. The RepA protein of plasmid pSC101 controls Escherichia coli cell division through the SOS response. Mol Microbiol. 2001;42:519-26 pubmed
    ..The mechanism reported here may help to limit variation in plasmid copy number and allow repopulation of cells with plasmids when copy number falls--potentially pre-empting plasmid loss in cultures of dividing cells. ..
  66. Madan Babu M, Teichmann S. Evolution of transcription factors and the gene regulatory network in Escherichia coli. Nucleic Acids Res. 2003;31:1234-44 pubmed
  67. Aertsen A, Van Houdt R, Vanoirbeek K, Michiels C. An SOS response induced by high pressure in Escherichia coli. J Bacteriol. 2004;186:6133-41 pubmed
    ..coli, characterized by the RecA and LexA-dependent expression of uvrA, recA, and sulA...
  68. Markham B, Little J, Mount D. Nucleotide sequence of the lexA gene of Escherichia coli K-12. Nucleic Acids Res. 1981;9:4149-61 pubmed
    A number of E. coli genes exhibit increased expression when the cellular DNA is damaged. In undamaged cells, lexA repressor limits the extent of their transcription, whereas, in damaged cells, the repressor is cleaved by a cellular ..
  69. Yamanaka T, Toyoshiba H, Sone H, Parham F, Portier C. The TAO-Gen algorithm for identifying gene interaction networks with application to SOS repair in E. coli. Environ Health Perspect. 2004;112:1614-21 pubmed
    ..The method is used to evaluate interactions between genes in the SOS signaling pathway in Escherichia coli using gene expression data where each gene in the network is over-expressed using plasmids inserts. ..
  70. Adikesavan A, Katsonis P, Marciano D, Lua R, Herman C, Lichtarge O. Separation of recombination and SOS response in Escherichia coli RecA suggests LexA interaction sites. PLoS Genet. 2011;7:e1002244 pubmed publisher
    RecA plays a key role in homologous recombination, the induction of the DNA damage response through LexA cleavage and the activity of error-prone polymerase in Escherichia coli...
  71. Akaboshi E. Dynamic profiles of DNA: analysis of CAP- and LexA protein-binding regions with endonucleases. DNA Cell Biol. 2005;24:161-72 pubmed
    We examined ssDNA and dsDNA containing a CAP-binding region or a lexA protein-binding region in the recA gene of Escherichia coli with endonucleases (E...
  72. Chattopadhyaya R, Ghosh K, Namboodiri V. Model of a LexA repressor dimer bound to recA operator. J Biomol Struct Dyn. 2000;18:181-97 pubmed
    A complete three dimensional model (RCSB000408; PDB code 1qaa) for the LexA repressor dimer bound to the recA operator site consistent with relevant biochemical and biophysical data for the repressor is proposed...
  73. Heitman J, Ivanenko T, Kiss A. DNA nicks inflicted by restriction endonucleases are repaired by a RecA- and RecB-dependent pathway in Escherichia coli. Mol Microbiol. 1999;33:1141-51 pubmed
    ..These observations suggest that an increased number of DNA nicks can overwhelm the repair capacity of DNA ligase, resulting in the conversion of a proportion of DNA nicks into DNA lesions that require recombination for repair. ..
  74. Brandsma J, Stoorvogel J, Van Sluis C, van de Putte P. Effect of lexA and ssb genes, present on a uvrA recombinant plasmid, on the UV survival of Escherichia coli K-12. Gene. 1982;18:77-85 pubmed
    The recombinant plasmid pJA01 contains, besides the uvrA gene, the genes lexA, ubiA and ssb. This plasmid does not fully complement a uvrA mutation in a Rec+ background...
  75. Butala M, Klose D, Hodnik V, Rems A, Podlesek Z, Klare J, et al. Interconversion between bound and free conformations of LexA orchestrates the bacterial SOS response. Nucleic Acids Res. 2011;39:6546-57 pubmed publisher
    ..In Escherichia coli, the SOS system is controlled by the interplay of the dimeric LexA transcriptional repressor with an inducer, the active RecA filament, which forms at sites of DNA damage and ..
  76. Hare J, Adhikari S, Lambert K, Hare A, Grice A. The Acinetobacter regulatory UmuDAb protein cleaves in response to DNA damage with chimeric LexA/UmuD characteristics. FEMS Microbiol Lett. 2012;334:57-65 pubmed publisher
    ..Like the self-cleaving serine proteases LexA and UmuD, UmuDAb required RecA for cleavage...
  77. Pacelli L, Edmiston S, Mount D. Isolation and characterization of amber mutations in the lexA gene of Escherichia coli K-12. J Bacteriol. 1979;137:568-73 pubmed
    We describe the isolation and characterization of amber mutations in the lexA gene of Escherichia coli K-12. These mutations, designated spr(Am), were isolated and characterized in a lexA tif sfi genetic background...
  78. Sutton M, Smith B, Godoy V, Walker G. The SOS response: recent insights into umuDC-dependent mutagenesis and DNA damage tolerance. Annu Rev Genet. 2000;34:479-497 pubmed
    ..Here we discuss the SOS response of E. coli and concentrate in particular on the roles of the umuD(+)C(+) gene products in promoting cell survival after DNA damage via TLS and a primitive DNA damage checkpoint. ..
  79. Kamenšek S, Podlesek Z, Gillor O, Zgur Bertok D. Genes regulated by the Escherichia coli SOS repressor LexA exhibit heterogeneous expression. BMC Microbiol. 2010;10:283 pubmed publisher
    ..In Escherichia coli the transcriptional repressor LexA controls a coordinated cellular response to DNA damage designated the SOS response...