seqA

Summary

Gene Symbol: seqA
Description: negative modulator of initiation of replication
Alias: ECK0675, JW0674, hsm-1
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Onogi T, Niki H, Yamazoe M, Hiraga S. The assembly and migration of SeqA-Gfp fusion in living cells of Escherichia coli. Mol Microbiol. 1999;31:1775-82 pubmed
    b>SeqA protein, which binds to hemi-methylated GATC sequences of DNA, is localized to discrete fluorescent foci in wild-type Escherichia coli cells. In this work, we observed cellular localization of the SeqA-Gfp fusion in living cells...
  2. Torheim N, Boye E, Løbner Olesen A, Stokke T, Skarstad K. The Escherichia coli SeqA protein destabilizes mutant DnaA204 protein. Mol Microbiol. 2000;37:629-38 pubmed
    ..The reason for the DnaA protein deficiency was found to be a rapid degradation of the mutant protein. Absence of SeqA protein stabilized the DnaA204 protein, increased the DnaA protein concentration and normalized the initiation mass ..
  3. Weitao T, Nordstrom K, DasGupta S. Escherichia coli cell cycle control genes affect chromosome superhelicity. EMBO Rep. 2000;1:494-9 pubmed
    ..supercoiling of Escherichia coli chromosome caused by mutations inactivating the cell cycle functions mukB and seqA. The amounts of the intercalative agent required to relax the supercoiled chromosome in mukB and seqA mutants were ..
  4. Nievera C, Torgue J, Grimwade J, Leonard A. SeqA blocking of DnaA-oriC interactions ensures staged assembly of the E. coli pre-RC. Mol Cell. 2006;24:581-92 pubmed
    ..After initiation, SeqA binds to hemimethylated oriC, sequestering oriC while levels of active DnaA are reduced, preventing reinitiation...
  5. Olsson J, Dasgupta S, Berg O, Nordström K. Eclipse period without sequestration in Escherichia coli. Mol Microbiol. 2002;44:1429-40 pubmed
    ..For strains with seqA, dam and damseqA mutants, the length of the eclipse period was 0.16, 0.40 and 0.32 generation times respectively...
  6. Fujikawa N, Kurumizaka H, Nureki O, Tanaka Y, Yamazoe M, Hiraga S, et al. Structural and biochemical analyses of hemimethylated DNA binding by the SeqA protein. Nucleic Acids Res. 2004;32:82-92 pubmed
    The Escherichia coli SeqA protein recognizes the 11 hemimethylated G-mA-T-C sites in the oriC region of the chromosome, and prevents replication over-initiation within one cell cycle...
  7. Bach T, Krekling M, Skarstad K. Excess SeqA prolongs sequestration of oriC and delays nucleoid segregation and cell division. EMBO J. 2003;22:315-23 pubmed
    ..The SeqA protein binds hemimethylated oriC in vitro...
  8. Fujikawa N, Kurumizaka H, Yamazoe M, Hiraga S, Yokoyama S. Identification of functional domains of the Escherichia coli SeqA protein. Biochem Biophys Res Commun. 2003;300:699-705 pubmed
    The Escherichia coli SeqA protein, a negative regulator of chromosomal DNA replication, prevents the overinitiation of replication within one cell cycle by binding to hemimethylated G-mA-T-C sequences in the replication origin, oriC...
  9. Guarné A, Zhao Q, Ghirlando R, Yang W. Insights into negative modulation of E. coli replication initiation from the structure of SeqA-hemimethylated DNA complex. Nat Struct Biol. 2002;9:839-43 pubmed
    The SeqA protein binds clusters of fully methylated or hemimethylated GATC sequences at oriC and negatively modulates the initiation of DNA replication...
  10. von Freiesleben U, Krekling M, Hansen F, Løbner Olesen A. The eclipse period of Escherichia coli. EMBO J. 2000;19:6240-8 pubmed
    ..The SeqA protein was absolutely required for the eclipse, and DnaA titration studies suggested that the SeqA protein ..

Detail Information

Publications71

  1. Onogi T, Niki H, Yamazoe M, Hiraga S. The assembly and migration of SeqA-Gfp fusion in living cells of Escherichia coli. Mol Microbiol. 1999;31:1775-82 pubmed
    b>SeqA protein, which binds to hemi-methylated GATC sequences of DNA, is localized to discrete fluorescent foci in wild-type Escherichia coli cells. In this work, we observed cellular localization of the SeqA-Gfp fusion in living cells...
  2. Torheim N, Boye E, Løbner Olesen A, Stokke T, Skarstad K. The Escherichia coli SeqA protein destabilizes mutant DnaA204 protein. Mol Microbiol. 2000;37:629-38 pubmed
    ..The reason for the DnaA protein deficiency was found to be a rapid degradation of the mutant protein. Absence of SeqA protein stabilized the DnaA204 protein, increased the DnaA protein concentration and normalized the initiation mass ..
  3. Weitao T, Nordstrom K, DasGupta S. Escherichia coli cell cycle control genes affect chromosome superhelicity. EMBO Rep. 2000;1:494-9 pubmed
    ..supercoiling of Escherichia coli chromosome caused by mutations inactivating the cell cycle functions mukB and seqA. The amounts of the intercalative agent required to relax the supercoiled chromosome in mukB and seqA mutants were ..
  4. Nievera C, Torgue J, Grimwade J, Leonard A. SeqA blocking of DnaA-oriC interactions ensures staged assembly of the E. coli pre-RC. Mol Cell. 2006;24:581-92 pubmed
    ..After initiation, SeqA binds to hemimethylated oriC, sequestering oriC while levels of active DnaA are reduced, preventing reinitiation...
  5. Olsson J, Dasgupta S, Berg O, Nordström K. Eclipse period without sequestration in Escherichia coli. Mol Microbiol. 2002;44:1429-40 pubmed
    ..For strains with seqA, dam and damseqA mutants, the length of the eclipse period was 0.16, 0.40 and 0.32 generation times respectively...
  6. Fujikawa N, Kurumizaka H, Nureki O, Tanaka Y, Yamazoe M, Hiraga S, et al. Structural and biochemical analyses of hemimethylated DNA binding by the SeqA protein. Nucleic Acids Res. 2004;32:82-92 pubmed
    The Escherichia coli SeqA protein recognizes the 11 hemimethylated G-mA-T-C sites in the oriC region of the chromosome, and prevents replication over-initiation within one cell cycle...
  7. Bach T, Krekling M, Skarstad K. Excess SeqA prolongs sequestration of oriC and delays nucleoid segregation and cell division. EMBO J. 2003;22:315-23 pubmed
    ..The SeqA protein binds hemimethylated oriC in vitro...
  8. Fujikawa N, Kurumizaka H, Yamazoe M, Hiraga S, Yokoyama S. Identification of functional domains of the Escherichia coli SeqA protein. Biochem Biophys Res Commun. 2003;300:699-705 pubmed
    The Escherichia coli SeqA protein, a negative regulator of chromosomal DNA replication, prevents the overinitiation of replication within one cell cycle by binding to hemimethylated G-mA-T-C sequences in the replication origin, oriC...
  9. Guarné A, Zhao Q, Ghirlando R, Yang W. Insights into negative modulation of E. coli replication initiation from the structure of SeqA-hemimethylated DNA complex. Nat Struct Biol. 2002;9:839-43 pubmed
    The SeqA protein binds clusters of fully methylated or hemimethylated GATC sequences at oriC and negatively modulates the initiation of DNA replication...
  10. von Freiesleben U, Krekling M, Hansen F, Løbner Olesen A. The eclipse period of Escherichia coli. EMBO J. 2000;19:6240-8 pubmed
    ..The SeqA protein was absolutely required for the eclipse, and DnaA titration studies suggested that the SeqA protein ..
  11. Norris V, Fralick J, Danchin A. A SeqA hyperstructure and its interactions direct the replication and sequestration of DNA. Mol Microbiol. 2000;37:696-702 pubmed
    ..In Escherichia coli, the formation of a SeqA hyperstructure via the phenomenon of local concentration may explain how the binding of SeqA to hemimethylated GATC ..
  12. Skarstad K, Lueder G, Lurz R, Speck C, Messer W. The Escherichia coli SeqA protein binds specifically and co-operatively to two sites in hemimethylated and fully methylated oriC. Mol Microbiol. 2000;36:1319-26 pubmed
    The Escherichia coli SeqA protein has been found to affect initiation of replication negatively, both in vivo and in vitro. The mechanism of inhibition is, however, not known...
  13. Kang S, Han J, Kim S, Park J, Hwang D. Aggregation of SeqA protein requires positively charged amino acids in the hinge region. Biochem Biophys Res Commun. 2007;360:63-9 pubmed
    b>SeqA proteins of Escherichia coli bound to the hemimethylated GATC sequences (hemi-sites) interact with each other and eventually form an aggregate...
  14. Morigen -, Odsbu I, Skarstad K. Growth rate dependent numbers of SeqA structures organize the multiple replication forks in rapidly growing Escherichia coli. Genes Cells. 2009;14:643-57 pubmed publisher
    ..The newly synthesized, hemimethylated DNA at each fork is bound by SeqA protein. The SeqA-DNA structures form distinct foci that can be observed by immunofluorescence microscopy...
  15. Lu M, Campbell J, Boye E, Kleckner N. SeqA: a negative modulator of replication initiation in E. coli. Cell. 1994;77:413-26 pubmed
    ..We report the identification of a gene required for sequestration and demonstrate that this gene, seqA, also serves as a negative modulator of the primary initiation process...
  16. Han J, Kang S, Kim S, Ko M, Hwang D. Binding of SeqA protein to hemi-methylated GATC sequences enhances their interaction and aggregation properties. J Biol Chem. 2004;279:30236-43 pubmed
    The SeqA protein regulates chromosome initiation and is involved in segregation in Escherichia coli. One SeqA protein binds to two hemi-methylated GATC sequences to form a stable SeqA-DNA complex...
  17. Brendler T, Austin S. Binding of SeqA protein to DNA requires interaction between two or more complexes bound to separate hemimethylated GATC sequences. EMBO J. 1999;18:2304-10 pubmed
    The SeqA protein binds to the post-replicative forms of the origins of replication of the Escherichia coli chromosome (oriC) and the P1 plasmid (P1oriR) at hemimethylated GATC adenine methylation sites...
  18. Joshi M, Magnan D, Montminy T, Lies M, Stepankiw N, Bates D. Regulation of sister chromosome cohesion by the replication fork tracking protein SeqA. PLoS Genet. 2013;9:e1003673 pubmed publisher
    ..coli is not currently understood. We report that the abundant fork tracking protein SeqA is a strong positive regulator of cohesion, and is responsible for markedly prolonged cohesion observed at "..
  19. Odsbu I, Klungsøyr H, Fossum S, Skarstad K. Specific N-terminal interactions of the Escherichia coli SeqA protein are required to form multimers that restrain negative supercoils and form foci. Genes Cells. 2005;10:1039-49 pubmed
    The Escherichia coli SeqA protein binds preferentially to hemimethylated DNA and is required for inactivation (sequestration) of newly formed origins...
  20. Han J, Kang S, Lee H, Kim H, Hwang D. Sequential binding of SeqA to paired hemi-methylated GATC sequences mediates formation of higher order complexes. J Biol Chem. 2003;278:34983-9 pubmed
    Preferential binding of the SeqA protein to hemi-methylated GATC sequences functions as a negative regulator for Escherichia coli initiation of chromosomal replication at oriC and is implicated in segregating replicated chromosomes for ..
  21. Waldminghaus T, Skarstad K. The Escherichia coli SeqA protein. Plasmid. 2009;61:141-50 pubmed publisher
    The Escherichia coli SeqA protein contributes to regulation of chromosome replication by preventing re-initiation at newly replicated origins. SeqA protein binds to new DNA which is hemimethylated at the adenine of GATC sequences...
  22. Kang S, Lee H, Han J, Hwang D. Interaction of SeqA and Dam methylase on the hemimethylated origin of Escherichia coli chromosomal DNA replication. J Biol Chem. 1999;274:11463-8 pubmed
    Preferential binding of SeqA protein to hemimethylated oriC, the origin of Escherichia coli chromosomal replication, delays methylation by Dam methylase...
  23. Wold S, Boye E, Slater S, Kleckner N, Skarstad K. Effects of purified SeqA protein on oriC-dependent DNA replication in vitro. EMBO J. 1998;17:4158-65 pubmed
    In vivo studies suggest that the Escherichia coli SeqA protein modulates replication initiation in two ways: by delaying initiation and by sequestering newly replicated origins from undergoing re-replication...
  24. Boye E, Stokke T, Kleckner N, Skarstad K. Coordinating DNA replication initiation with cell growth: differential roles for DnaA and SeqA proteins. Proc Natl Acad Sci U S A. 1996;93:12206-11 pubmed
    ..Furthermore, a comparison between wild-type and seqA mutant cells shows that initiation occurs at a 10-20% lower mass in the seqA mutant, providing direct evidence that ..
  25. Kang S, Han J, Park J, Skarstad K, Hwang D. SeqA protein stimulates the relaxing and decatenating activities of topoisomerase IV. J Biol Chem. 2003;278:48779-85 pubmed
    The SeqA protein, which prevents overinitiation of chromosome replication, has been suggested to also participate in the segregation of chromosomes in Escherichia coli...
  26. Foti J, Persky N, Ferullo D, Lovett S. Chromosome segregation control by Escherichia coli ObgE GTPase. Mol Microbiol. 2007;65:569-81 pubmed
    ..Localization of the SeqA DNA binding protein, normally seen as punctate foci, however, was disturbed...
  27. Hiraga S, Ichinose C, Niki H, Yamazoe M. Cell cycle-dependent duplication and bidirectional migration of SeqA-associated DNA-protein complexes in E. coli. Mol Cell. 1998;1:381-7 pubmed
    Using immunofluorescence microscopy, we have found that SeqA protein, a regulator of replication initiation, is localized as discrete fluorescent foci in E. coli wild-type cells...
  28. Guarné A, Brendler T, Zhao Q, Ghirlando R, Austin S, Yang W. Crystal structure of a SeqA-N filament: implications for DNA replication and chromosome organization. EMBO J. 2005;24:1502-11 pubmed
    Escherichia coli SeqA binds clusters of transiently hemimethylated GATC sequences and sequesters the origin of replication, oriC, from methylation and premature reinitiation...
  29. Kang S, Han J, Kim K, Yang H, Lee K, Hong C, et al. Dimeric configuration of SeqA protein bound to a pair of hemi-methylated GATC sequences. Nucleic Acids Res. 2005;33:1524-31 pubmed
    The binding of SeqA protein to hemi-methylated GATC sequences (hemi-sites) regulates chromosome initiation and the segregation of replicated chromosome in Escherichia coli...
  30. Foti J, Schienda J, Sutera V, Lovett S. A bacterial G protein-mediated response to replication arrest. Mol Cell. 2005;17:549-60 pubmed
    ..ObgE overexpression caused SeqA foci, normally localized to replication forks, to spread extensively within the cell...
  31. Klungsøyr H, Skarstad K. Positive supercoiling is generated in the presence of Escherichia coli SeqA protein. Mol Microbiol. 2004;54:123-31 pubmed
    In Escherichia coli, the SeqA protein is known as a negative regulator of chromosome replication. This protein is also suggested to have a role in chromosome organization...
  32. Lee H, Kang S, Bae S, Choi B, Hwang D. SeqA protein aggregation is necessary for SeqA function. J Biol Chem. 2001;276:34600-6 pubmed
    The binding of SeqA protein to hemimethylated GATC sequences is important in the negative modulation of chromosomal initiation at oriC, and in the formation of SeqA foci necessary for Escherichia coli chromosome segregation...
  33. Babic A, Lindner A, Vulic M, Stewart E, Radman M. Direct visualization of horizontal gene transfer. Science. 2008;319:1533-6 pubmed publisher
    ..Using a fluorescent protein fusion, SeqA-YFP, we have visualized this process in real time and in single cells of Escherichia coli...
  34. Fossum S, Søreide S, Skarstad K. Lack of SeqA focus formation, specific DNA binding and proper protein multimerization in the Escherichia coli sequestration mutant seqA2. Mol Microbiol. 2003;47:619-32 pubmed
    ..mutants discovered in a screen for the inability to sequester hemimethylated origins have been mapped to the seqA gene...
  35. Kaguni J. DnaA: controlling the initiation of bacterial DNA replication and more. Annu Rev Microbiol. 2006;60:351-75 pubmed
    ..A major player in this pathway is SeqA protein and involves its ability to bind preferentially to oriC when it is hemi-methylated...
  36. Kouzminova E, Rotman E, Macomber L, Zhang J, Kuzminov A. RecA-dependent mutants in Escherichia coli reveal strategies to avoid chromosomal fragmentation. Proc Natl Acad Sci U S A. 2004;101:16262-7 pubmed
    ..The fur, ubiE, and ubiH mutants are likely to have increased levels of reactive oxygen species. The seqA, topA mutants and an insertion in smtA perturbing the downstream mukFEB genes affect nucleoid administration...
  37. Yamazoe M, Adachi S, Kanaya S, Ohsumi K, Hiraga S. Sequential binding of SeqA protein to nascent DNA segments at replication forks in synchronized cultures of Escherichia coli. Mol Microbiol. 2005;55:289-98 pubmed
    To demonstrate that sequestration A (SeqA) protein binds preferentially to hemimethylated GATC sequences at replication forks and forms clusters in Escherichia coli growing cells, we analysed, by the chromatin immunoprecipitation (ChIP) ..
  38. Sutera V, Lovett S. The role of replication initiation control in promoting survival of replication fork damage. Mol Microbiol. 2006;60:229-39 pubmed
    ..Dam's role in tolerance of DNA damage is to provide binding sites for SeqA, because seqA mutants showed similar sensitivity that was genetically epistatic to dam...
  39. Brendler T, Abeles A, Austin S. A protein that binds to the P1 origin core and the oriC 13mer region in a methylation-specific fashion is the product of the host seqA gene. EMBO J. 1995;14:4083-9 pubmed
    ..It proved to be the product of the seqA gene that acts in the negative control of oriC by sequestration...
  40. Ferullo D, Lovett S. The stringent response and cell cycle arrest in Escherichia coli. PLoS Genet. 2008;4:e1000300 pubmed publisher
    ..Arrest of replication and inhibition of colony formation by ppGpp accumulation is relieved in seqA and dam mutants, although other aspects of the stringent response appear to be intact...
  41. Rotman E, Khan S, Kouzminova E, Kuzminov A. Replication fork inhibition in seqA mutants of Escherichia coli triggers replication fork breakage. Mol Microbiol. 2014;93:50-64 pubmed publisher
    b>SeqA protein negatively regulates replication initiation in Escherichia coli and is also proposed to organize maturation and segregation of the newly replicated DNA...
  42. von Freiesleben U, Rasmussen K, Schaechter M. SeqA limits DnaA activity in replication from oriC in Escherichia coli. Mol Microbiol. 1994;14:763-72 pubmed
    ..A similar mutation in this gene, named seqA1, has also been isolated. Here we show that the product of the seqA gene, SeqA, normally acts as an inhibitor of chromosomal initiation...
  43. Weitao T, Nordstrom K, DasGupta S. Mutual suppression of mukB and seqA phenotypes might arise from their opposing influences on the Escherichia coli nucleoid structure. Mol Microbiol. 1999;34:157-68 pubmed
    A strain of Escherichia coli in which both the seqA and mukB genes were inactivated displayed partial suppressions of their individual phenotypes...
  44. Hiraga S, Ichinose C, Onogi T, Niki H, Yamazoe M. Bidirectional migration of SeqA-bound hemimethylated DNA clusters and pairing of oriC copies in Escherichia coli. Genes Cells. 2000;5:327-41 pubmed
    We previously found that SeqA protein, which binds preferentially to newly replicated hemimethylated DNA, is localized as discrete fluorescent foci in Escherichia coli cells...
  45. Brendler T, Sawitzke J, Sergueev K, Austin S. A case for sliding SeqA tracts at anchored replication forks during Escherichia coli chromosome replication and segregation. EMBO J. 2000;19:6249-58 pubmed
    b>SeqA is an Escherichia coli DNA-binding protein that acts at replication origins and controls DNA replication. However, binding is not exclusive to origins...
  46. Molina F, Skarstad K. Replication fork and SeqA focus distributions in Escherichia coli suggest a replication hyperstructure dependent on nucleotide metabolism. Mol Microbiol. 2004;52:1597-612 pubmed
    ..of cells growing with four different growth and replication rates, and compared these with the distributions of SeqA foci...
  47. Slater S, Wold S, Lu M, Boye E, Skarstad K, Kleckner N. E. coli SeqA protein binds oriC in two different methyl-modulated reactions appropriate to its roles in DNA replication initiation and origin sequestration. Cell. 1995;82:927-36 pubmed
    The seqA gene negatively modulates replication initiation at the E. coli origin, oriC...
  48. Waldminghaus T, Weigel C, Skarstad K. Replication fork movement and methylation govern SeqA binding to the Escherichia coli chromosome. Nucleic Acids Res. 2012;40:5465-76 pubmed publisher
    In Escherichia coli, the SeqA protein binds specifically to GATC sequences which are methylated on the A of the old strand but not on the new strand...
  49. Bach T, Morigen -, Skarstad K. The initiator protein DnaA contributes to keeping new origins inactivated by promoting the presence of hemimethylated DNA. J Mol Biol. 2008;384:1076-85 pubmed publisher
    ..The prolonged period of hemimethylation has been attributed to the presence of bound SeqA protein...
  50. Fossum S, Crooke E, Skarstad K. Organization of sister origins and replisomes during multifork DNA replication in Escherichia coli. EMBO J. 2007;26:4514-22 pubmed
    ..1-0.2 generations. The role of origin inactivation (sequestration) by the SeqA protein in origin colocalization was studied by comparing sequestration-deficient mutants with wild-type cells...
  51. Nordström K, Dasgupta S. Copy-number control of the Escherichia coli chromosome: a plasmidologist's view. EMBO Rep. 2006;7:484-9 pubmed
    ..Superimposed on this basic mechanism are at least three systems that secure the synchronous initiation of multiple origins; however, these mechanisms are not essential for maintaining the copy number. ..
  52. Camara J, Breier A, Brendler T, Austin S, Cozzarelli N, Crooke E. Hda inactivation of DnaA is the predominant mechanism preventing hyperinitiation of Escherichia coli DNA replication. EMBO Rep. 2005;6:736-41 pubmed
    ..proposed: titration of free DnaA initiator protein by the datA locus, sequestration of newly replicated origins by SeqA protein and regulatory inactivation of DnaA (RIDA), in which active ATP-DnaA is converted to the inactive ADP-bound ..
  53. Hiraga S. Dynamic localization of bacterial and plasmid chromosomes. Annu Rev Genet. 2000;34:21-59 pubmed
    ..coli, but not B. subtilis, the chromosomal DNA is fully methylated by DNA adenine methyltransferase. The E. coli SeqA protein, which binds preferentially to hemimethylated nascent DNA strands, exists as discrete foci in vivo...
  54. Sikora A, Zielke R, Wegrzyn A, Wegrzyn G. DNA replication defect in the Escherichia coli cgtA(ts) mutant arising from reduced DnaA levels. Arch Microbiol. 2006;185:340-7 pubmed
    ..expression of dnaA were specific as analogous expression of another gene coding for a replication regulator, seqA, had no significant changes in growth and DNA synthesis in the cgtA mutant...
  55. Olsson J, Nordström K, Hjort K, Dasgupta S. Eclipse-synchrony relationship in Escherichia coli strains with mutations affecting sequestration, initiation of replication and superhelicity of the bacterial chromosome. J Mol Biol. 2003;334:919-31 pubmed
    ..Sequestration is also believed to be responsible for initiation synchrony, since inactivation of either the seqA or the dam gene abolishes synchrony while drastically reducing the eclipse...
  56. Słomińska M, Konopa G, Ostrowska J, Kedzierska B, Wegrzyn G, Wegrzyn A. SeqA-mediated stimulation of a promoter activity by facilitating functions of a transcription activator. Mol Microbiol. 2003;47:1669-79 pubmed
    It was demonstrated recently that the SeqA protein, a main negative regulator of Escherichia coli chromosome replication initiation, is also a specific transcription factor...
  57. Lu M, Kleckner N. Molecular cloning and characterization of the pgm gene encoding phosphoglucomutase of Escherichia coli. J Bacteriol. 1994;176:5847-51 pubmed
    ..The predicted amino acid sequence of the pgm gene is highly conserved in E. coli, Acetobacter xylinum, Saccharomyces cerevisiae, rabbits, and humans. pgm deletion mutant strains are deficient in phosphoglucomutase activity. ..
  58. Taghbalout A, Landoulsi A, Kern R, Yamazoe M, Hiraga S, Holland B, et al. Competition between the replication initiator DnaA and the sequestration factor SeqA for binding to the hemimethylated chromosomal origin of E. coli in vitro. Genes Cells. 2000;5:873-884 pubmed
    ..oriC) in Escherichia coli enters a hemimethylated state at Dam methylation sites which are recognized by the SeqA protein. SeqA binds preferentially to hemimethylated GATC sequences of DNA in vitro...
  59. Helgesen E, Fossum Raunehaug S, Sætre F, Schink K, Skarstad K. Dynamic Escherichia coli SeqA complexes organize the newly replicated DNA at a considerable distance from the replisome. Nucleic Acids Res. 2015;43:2730-43 pubmed publisher
    The Escherichia coli SeqA protein binds to newly replicated, hemimethylated DNA behind replication forks and forms structures consisting of several hundred SeqA molecules bound to about 100 kb of DNA...
  60. Slominska M, Wahl A, Wegrzyn G, Skarstad K. Degradation of mutant initiator protein DnaA204 by proteases ClpP, ClpQ and Lon is prevented when DNA is SeqA-free. Biochem J. 2003;370:867-71 pubmed
    ..The mutant DnaA protein is stabilized by the lack of SeqA protein. This stabilization was also observed in a dam mutant where the chromosome remains unmethylated...
  61. Herrick J, Kern R, Guha S, Landoulsi A, Fayet O, Malki A, et al. Parental strand recognition of the DNA replication origin by the outer membrane in Escherichia coli. EMBO J. 1994;13:4695-703 pubmed
    ..The purified LacZ-HobH fusion protein specifically binds oriC DNA at the same preferential sites as the membrane. A mutant of the hobH gene reveals partial asynchronous initiation of DNA replication. ..
  62. Chung Y, Guarné A. Crystallization and preliminary X-ray diffraction analysis of SeqA bound to a pair of hemimethylated GATC sites. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2008;64:567-71 pubmed publisher
    Escherichia coli SeqA is a negative regulator of DNA replication. The SeqA protein forms a high-affinity complex with newly replicated DNA at the origin of replication and thus prevents premature re-initiation events...
  63. Boye E, Løbner Olesen A, Skarstad K. Limiting DNA replication to once and only once. EMBO Rep. 2000;1:479-83 pubmed
    ..All cells have developed mechanisms for origin inactivation, but those of other bacteria and eukaryotic cells are clearly distinct from those of E. coli. Possible differences and similarities are discussed. ..
  64. Łyzeń R, Wegrzyn G, Wegrzyn A, Szalewska Pałasz A. Stimulation of the lambda pR promoter by Escherichia coli SeqA protein requires downstream GATC sequences and involves late stages of transcription initiation. Microbiology. 2006;152:2985-92 pubmed
    Escherichia coli SeqA protein is a major negative regulator of chromosomal DNA replication acting by sequestration, and thus inactivation, of newly formed oriC regions...
  65. Daghfous D, Chatti A, Hammami R, Landoulsi A. Modeling of the full-length Escherichia coli SeqA protein, in complex with DNA. Pathol Biol (Paris). 2009;57:e61-6 pubmed publisher
    The Escherichia coli SeqA protein, a negative regulator of chromosome DNA replication, prevents the overinitiation of replication within one cell cycle by binding to hemimethylated GATC sequences in the replication origin, oriC...
  66. Slominska M, Wegrzyn A, Konopa G, Skarstad K, Wegrzyn G. SeqA, the Escherichia coli origin sequestration protein, is also a specific transcription factor. Mol Microbiol. 2001;40:1371-9 pubmed
    The SeqA protein is a negative regulator of initiation of DNA replication in the Escherichia coli chromosome. Here, we demonstrate that SeqA stimulates transcription from the bacteriophage lambda pR promoter both in vivo and in vitro...
  67. Lyzeń R, Kochanowska M, Wegrzyn G, Szalewska Pałasz A. IHF- and SeqA-binding sites, present in plasmid cloning vectors, may significantly influence activities of promoters. Plasmid. 2008;60:125-30 pubmed publisher
    ..The IHF consensus sites are abundant and they can bind the IHF protein as shown in in vitro studies. The SeqA protein has a role in the complex regulation of pR activity, together with other factors altering DNA topology...
  68. Rotman E, Bratcher P, Kuzminov A. Reduced lipopolysaccharide phosphorylation in Escherichia coli lowers the elevated ori/ter ratio in seqA mutants. Mol Microbiol. 2009;72:1273-92 pubmed publisher
    The seqA defect in Escherichia coli increases the ori/ter ratio and causes chromosomal fragmentation, making seqA mutants dependent on recombinational repair (the seqA recA colethality)...
  69. Molt K, Sutera V, Moore K, Lovett S. A role for nonessential domain II of initiator protein, DnaA, in replication control. Genetics. 2009;183:39-49 pubmed publisher
    ..These suppressors suppressed the replication control defects of mutants in seqA alone and genetically mapped to the essential dnaA replication initiator gene...
  70. Nordstrom K, DasGupta S. Partitioning of the Escherichia coli chromosome: superhelicity and condensation. Biochimie. 2001;83:41-8 pubmed
    ..E. coli strains, lacking mukB or seqA functions, are defective in segregation and cell division...