Gene Symbol: dnaQ
Description: DNA polymerase III epsilon subunit
Alias: ECK0215, JW0205, mutD
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Derose E, Darden T, Harvey S, Gabel S, Perrino F, Schaaper R, et al. Elucidation of the epsilon-theta subunit interface of Escherichia coli DNA polymerase III by NMR spectroscopy. Biochemistry. 2003;42:3635-44 pubmed
    ..These chemical shift mapping results also suggest an explanation for how the unstable dnaQ49 mutator phenotype of epsilon may be stabilized by binding theta. ..
  2. Zahra R, Blackwood J, Sales J, Leach D. Proofreading and secondary structure processing determine the orientation dependence of CAG x CTG trinucleotide repeat instability in Escherichia coli. Genetics. 2007;176:27-41 pubmed
    ..of CAG x CTG trinucleotide repeat deletion is determined by the proofreading subunit of DNA polymerase III (DnaQ) in the presence of the hairpin nuclease SbcCD (Rad50/Mre11)...
  3. Scheuermann R, Echols H. A separate editing exonuclease for DNA replication: the epsilon subunit of Escherichia coli DNA polymerase III holoenzyme. Proc Natl Acad Sci U S A. 1984;81:7747-51 pubmed
    ..the fidelity of DNA replication in vivo and the activity of 3'----5' exonuclease assayed in vitro are found in the dnaQ gene, which specifies the epsilon subunit...
  4. Stukenberg P, Studwell Vaughan P, O Donnell M. Mechanism of the sliding beta-clamp of DNA polymerase III holoenzyme. J Biol Chem. 1991;266:11328-34 pubmed
    ..Hence, the high processivity of the holoenzyme is rooted in a "sliding clamp" of beta on DNA that tethers the polymerase to the primed template. Implications for transcription and translation are discussed. ..
  5. McInerney P, Johnson A, Katz F, O Donnell M. Characterization of a triple DNA polymerase replisome. Mol Cell. 2007;27:527-38 pubmed
    ..We propose that two polymerases can function on the lagging strand and that the third DNA polymerase can act as a reserve enzyme to overcome certain types of obstacles to the replication fork. ..
  6. Hamdan S, Bulloch E, Thompson P, Beck J, Yang J, Crowther J, et al. Hydrolysis of the 5'-p-nitrophenyl ester of TMP by the proofreading exonuclease (epsilon) subunit of Escherichia coli DNA polymerase III. Biochemistry. 2002;41:5266-75 pubmed
  7. Miller H, Perrino F. Kinetic mechanism of the 3'-->5' proofreading exonuclease of DNA polymerase III. Analysis by steady state and pre-steady state methods. Biochemistry. 1996;35:12919-25 pubmed
    ..The kinetics for exonucleolytic degradation of single-stranded, paired, and mispaired oligonucleotides support the model that the rate-limiting step in exonucleolytic proofreading of DNA by epsilon subunit is the DNA-melting step. ..
  8. Stefan A, Reggiani L, Cianchetta S, Radeghieri A, Gonzalez Vara y Rodriguez A, Hochkoeppler A. Silencing of the gene coding for the epsilon subunit of DNA polymerase III slows down the growth rate of Escherichia coli populations. FEBS Lett. 2003;546:295-9 pubmed
    ..by the multimeric enzyme DNA polymerase III; the relevance, in vivo, of the epsilon subunit (encoded by dnaQ) for processivity and fidelity of DNA polymerase III has been evaluated...
  9. Lehtinen D, Perrino F. Dysfunctional proofreading in the Escherichia coli DNA polymerase III core. Biochem J. 2004;384:337-48 pubmed
    ..A novel mutagenesis strategy was used to identify 23 dnaQ alleles that exhibit a mutator phenotype in vivo...

More Information


  1. Jergic S, Horan N, Elshenawy M, Mason C, Urathamakul T, Ozawa K, et al. A direct proofreader-clamp interaction stabilizes the Pol III replicase in the polymerization mode. EMBO J. 2013;32:1322-33 pubmed publisher
  2. Studwell P, O Donnell M. Processive replication is contingent on the exonuclease subunit of DNA polymerase III holoenzyme. J Biol Chem. 1990;265:1171-8 pubmed
    ..In light of these results the significance of the polymerase and exonuclease activities residing in two separate polypeptides is discussed. ..
  3. Scheuermann R, Tam S, Burgers P, Lu C, Echols H. Identification of the epsilon-subunit of Escherichia coli DNA polymerase III holoenzyme as the dnaQ gene product: a fidelity subunit for DNA replication. Proc Natl Acad Sci U S A. 1983;80:7085-9 pubmed
    ..coli occur in a single gene, dnaQ. To define further the role of the dnaQ gene, we have used two-dimensional gel electrophoresis to compare the ..
  4. Maki H, Kornberg A. Proofreading by DNA polymerase III of Escherichia coli depends on cooperative interaction of the polymerase and exonuclease subunits. Proc Natl Acad Sci U S A. 1987;84:4389-92 pubmed
  5. Taft Benz S, Schaaper R. The theta subunit of Escherichia coli DNA polymerase III: a role in stabilizing the epsilon proofreading subunit. J Bacteriol. 2004;186:2774-80 pubmed
    ..mismatch-repair-defective mutL backgrounds, (ii) strong DeltaholE mutator effects in certain proofreading-impaired dnaQ strains, and (iii) yeast two- and three-hybrid experiments demonstrating enhancement of alpha-epsilon interactions ..
  6. Kim D, McHenry C. In vivo assembly of overproduced DNA polymerase III. Overproduction, purification, and characterization of the alpha, alpha-epsilon, and alpha-epsilon-theta subunits. J Biol Chem. 1996;271:20681-9 pubmed
    ..and in vivo assembly of DNA polymerase III core, artificial operons containing the three structural genes, dnaE, dnaQ, and holE, were placed in an expression plasmid...
  7. Taft Benz S, Schaaper R. The C-terminal domain of dnaQ contains the polymerase binding site. J Bacteriol. 1999;181:2963-5 pubmed
    The Escherichia coli dnaQ gene encodes the 3'-->5' exonucleolytic proofreading (epsilon) subunit of DNA polymerase III (Pol III)...
  8. McHenry C, Crow W. DNA polymerase III of Escherichia coli. Purification and identification of subunits. J Biol Chem. 1979;254:1748-53 pubmed
    ..Our preparation has both the 3' leads to 5' and 5' leads to 3' exonuclease activities previously assigned to DNA polymerase III (Livingston, D., and Richardson, C. (1975) J. Biol. Chem. 250, 470-478). ..
  9. Chikova A, Schaaper R. The bacteriophage P1 hot gene product can substitute for the Escherichia coli DNA polymerase III {theta} subunit. J Bacteriol. 2005;187:5528-36 pubmed
    ..The ability of hot to substitute for holE was also observed with other, although not all, dnaQ mutator alleles tested...
  10. Hamdan S, Carr P, Brown S, Ollis D, Dixon N. Structural basis for proofreading during replication of the Escherichia coli chromosome. Structure. 2002;10:535-46 pubmed
    ..The protein structure is built around a core five-stranded beta sheet that is a common feature of members of the DnaQ superfamily...
  11. Taft Benz S, Schaaper R. Mutational analysis of the 3'-->5' proofreading exonuclease of Escherichia coli DNA polymerase III. Nucleic Acids Res. 1998;26:4005-11 pubmed
    ..epsilon performs these joint structural and catalytic functions, we have investigated a set of 20 newly isolated dnaQ mutator mutants...
  12. Perrino F, Harvey S, McNeill S. Two functional domains of the epsilon subunit of DNA polymerase III. Biochemistry. 1999;38:16001-9 pubmed
    ..These data support the concept that epsilon contains a catalytic domain located within the N-terminal region and an alpha-association domain located within the C-terminal region of the protein...
  13. Hamdan S, Brown S, Thompson P, Yang J, Carr P, Ollis D, et al. Preliminary X-ray crystallographic and NMR studies on the exonuclease domain of the epsilon subunit of Escherichia coli DNA polymerase III. J Struct Biol. 2000;131:164-9 pubmed
    ..2 mm x 0.2 mm x 1.0 mm, grow over about 2 weeks at 4 degrees C, and diffract X-rays to 2.0 A. The space group was determined to be P4(n)2(1)2 (n = 0, 1, 2, 3), with unit cell dimensions a = 60.8 A, c = 111.4 A. ..
  14. Pintacuda G, Park A, Keniry M, Dixon N, Otting G. Lanthanide labeling offers fast NMR approach to 3D structure determinations of protein-protein complexes. J Am Chem Soc. 2006;128:3696-702 pubmed
    ..Degeneracies in the mutual orientation of the protein structures were resolved by the use of two different lanthanide ions, Dy3+ and Er3+...
  15. Kirby T, Harvey S, Derose E, Chalov S, Chikova A, Perrino F, et al. Structure of the Escherichia coli DNA polymerase III epsilon-HOT proofreading complex. J Biol Chem. 2006;281:38466-71 pubmed
    ..This structure provides insight into how HOT and, by implication, may stabilize the epsilon subunit, thus promoting efficient proofreading during chromosomal replication. ..
  16. Keniry M, Park A, Owen E, Hamdan S, Pintacuda G, Otting G, et al. Structure of the theta subunit of Escherichia coli DNA polymerase III in complex with the epsilon subunit. J Bacteriol. 2006;188:4464-73 pubmed
    ..The pseudocontact shifts indicated that the helices of theta are located about 15 A or farther from the lanthanide ion in the active site of epsilon186, in agreement with the extensive biochemical data for the theta-epsilon system. ..
  17. Ozawa K, Jergic S, Park A, Dixon N, Otting G. The proofreading exonuclease subunit epsilon of Escherichia coli DNA polymerase III is tethered to the polymerase subunit alpha via a flexible linker. Nucleic Acids Res. 2008;36:5074-82 pubmed publisher
    ..This distinguishes the alpha : epsilon complex from other proofreading polymerases, which have a more rigid multidomain structure. ..
  18. Stefan A, Tabler M, Hochkoeppler A. Efficient silencing of the gene coding for the epsilon subunit of DNA polymerase III in Escherichia coli is triggered by antisense RNAs featuring stability in vivo. FEMS Microbiol Lett. 2007;270:277-83 pubmed
    The Escherichia coli gene dnaQ coding for the epsilon subunit of DNA polymerase III was suppressed in vivo via antisense RNAs...
  19. Maki H, Maki S, Kornberg A. DNA Polymerase III holoenzyme of Escherichia coli. IV. The holoenzyme is an asymmetric dimer with twin active sites. J Biol Chem. 1988;263:6570-8 pubmed
  20. Maki S, Kornberg A. DNA polymerase III holoenzyme of Escherichia coli. III. Distinctive processive polymerases reconstituted from purified subunits. J Biol Chem. 1988;263:6561-9 pubmed
  21. Maki H, Akiyama M, Horiuchi T, Sekiguchi M. Molecular mechanisms of replicational fidelity in Escherichia coli. Basic Life Sci. 1990;52:299-308 pubmed
    ..the alpha subunit, encoded by the dnaE gene, has a polymerase activity, while the epsilon subunit, encoded by the dnaQ gene, is a proofreader with a 3'-5' exonuclease activity...
  22. Ozawa K, Horan N, Robinson A, Yagi H, Hill F, Jergic S, et al. Proofreading exonuclease on a tether: the complex between the E. coli DNA polymerase III subunits ?, epsilon, ? and ? reveals a highly flexible arrangement of the proofreading domain. Nucleic Acids Res. 2013;41:5354-67 pubmed publisher
    ..Structural models of the ???:?2 replicase complex with primer-template DNA combine all available structural data. ..
  23. Nowosielska A, Wrzesiński M, Nieminuszczy J, Janion C, Grzesiuk E. Mutator activity and specificity of Escherichia coli dnaQ49 allele--effect of umuDC products. Mutat Res. 2005;572:113-22 pubmed
    The high fidelity of DNA replication in Escherichia coli is ensured by the alpha (DnaE) and epsilon (DnaQ) subunits of DNA polymerase providing insertion fidelity, 3'-->5' exonuclease proofreading activity, and by the dam-directed ..
  24. Laranjo L, Gross S, Zeiger D, Lovett S. SSB recruitment of Exonuclease I aborts template-switching in Escherichia coli. DNA Repair (Amst). 2017;57:12-16 pubmed publisher
  25. LaDuca R, Fay P, Chuang C, McHenry C, Bambara R. Site-specific pausing of deoxyribonucleic acid synthesis catalyzed by four forms of Escherichia coli DNA polymerase III. Biochemistry. 1983;22:5177-88 pubmed
    ..Additionally, a nucleotide composition specificity of pause sites has been observed. ..
  26. Livingston D, Richardson C. Deoxyribonucleic acid polymerase III of Escherichia coli. Characterization of associated exonuclease activities. J Biol Chem. 1975;250:470-8 pubmed
    ..The 5-3 exonuclease attacks ultraviolet-irradiated duplex DNA which has first been incised by the Micrococcus luteus endonuclease specific for thymine dimers in DNA. ..
  27. Montón Silva A, Lapenta F, Stefan A, Dal Piaz F, Ceccarelli A, Perrone A, et al. Simultaneous ternary extension of DNA catalyzed by a trimeric replicase assembled in vivo. Biochem Biophys Res Commun. 2015;462:14-20 pubmed publisher
    ..Our observations indicate that trimeric DNA replicases reduce the gap between leading and lagging strand synthesis. ..
  28. Cox E, Horner D. DNA sequence and coding properties of mutD(dnaQ) a dominant Escherichia coli mutator gene. J Mol Biol. 1986;190:113-7 pubmed
    The mutD(dnaQ) gene in Escherichia coli codes for the epsilon subunit of the DNA polymerase pol III holoenzyme. Previous work has shown that this gene lies adjacent to the gene coding for RNase H (rnh)...
  29. Borden A, O Grady P, Vandewiele D, Fernández de Henestrosa A, Lawrence C, Woodgate R. Escherichia coli DNA polymerase III can replicate efficiently past a T-T cis-syn cyclobutane dimer if DNA polymerase V and the 3' to 5' exonuclease proofreading function encoded by dnaQ are inactivated. J Bacteriol. 2002;184:2674-81 pubmed
    ..This mutant polymerase does not replicate past the much more distorted T-T (6-4) photoadduct, however, suggesting that it may only replicate past lesions, like the T-T dimer, that form base pairs normally. ..
  30. Kaasch M, Kaasch J, Quinones A. Expression of the dnaN and dnaQ genes of Escherichia coli is inducible by mitomycin C. Mol Gen Genet. 1989;219:187-92 pubmed
    The dnaN and dnaQ genes encode the beta subunit and the epsilon subunit of the DNA polymerase III holoenzyme. Using translational fusions to lacZ we found that DNA damage caused by mitomycin C induces expression of the dnaA and dnaQ genes...
  31. Nomura T, Aiba H, Ishihama A. Transcriptional organization of the convergent overlapping dnaQ-rnh genes of Escherichia coli. J Biol Chem. 1985;260:7122-5 pubmed
    The transcriptional organization was determined for the DNA polymerase III epsilon subunit (dnaQ) and the ribonuclease H (rnh) genes, which are closely spaced and organized in a face-to-face system (Maki, H., Horiuchi, T...
  32. Pham P, Olson M, McHenry C, Schaaper R. Mismatch extension by Escherichia coli DNA polymerase III holoenzyme. J Biol Chem. 1999;274:3705-10 pubmed
    ..The preference of polymerase III HE for misalignment extension over direct mismatch extension provides a basis for explaining the in vitro (-1)-frameshift specificity of polymerase III HE. ..
  33. Jonczyk P, Nowicka A, Fijałkowska I, Schaaper R, Ciesla Z. In vivo protein interactions within the Escherichia coli DNA polymerase III core. J Bacteriol. 1998;180:1563-6 pubmed
    ..physiological role of the interactions between the DnaE (alpha subunit [possessing DNA polymerase activity]) and DnaQ (epsilon subunit [possessing 3'-->5' exonucleolytic proofreading activity]) proteins...
  34. Cull M, McHenry C. Purification of Escherichia coli DNA polymerase III holoenzyme. Methods Enzymol. 1995;262:22-35 pubmed
  35. Saveson C, Lovett S. Enhanced deletion formation by aberrant DNA replication in Escherichia coli. Genetics. 1997;146:457-70 pubmed
    ..Especially large increases were observed in strains mutant in dnaQ the epsilon editing subunit of Pol III, and dnaB, the replication fork helicase...
  36. Burgers P, Kornberg A. The cycling of Escherichia coli DNA polymerase III holoenzyme in replication. J Biol Chem. 1983;258:7669-75 pubmed
  37. O Grady P, Borden A, Vandewiele D, Ozgenc A, Woodgate R, Lawrence C. Intrinsic polymerase activities of UmuD'(2)C and MucA'(2)B are responsible for their different mutagenic properties during bypass of a T-T cis-syn cyclobutane dimer. J Bacteriol. 2000;182:2285-91 pubmed
    ..of dimer bypass, the error rate of bypass, and the resulting mutation spectrum in mutants carrying a deletion of dnaQ (epsilon subunit) or holE (theta subunit) or carrying the dnaQ allele mutD5, which is deficient in proofreading but ..
  38. Quinones A, Neumann S. The ssb-113 allele suppresses the dnaQ49 mutator and alters DNA supercoiling in Escherichia coli. Mol Microbiol. 1997;25:237-46 pubmed
    Mutations in the dnaQ gene, which encodes the proofreading epsilon-subunit of the DNA polymerase III holoenzyme, lead to a mutator phenotype caused by enhanced error rates during DNA replication...
  39. Pages V, Janel Bintz R, Fuchs R. Pol III proofreading activity prevents lesion bypass as evidenced by its molecular signature within E.coli cells. J Mol Biol. 2005;352:501-9 pubmed
    ..These data are corroborated using a colony-based bypass assay. ..
  40. Helling R. Selection of a mutant of Escherichia coli which has high mutation rates. J Bacteriol. 1968;96:975-80 pubmed
    ..This mutation (mut-2) and the Treffers' mutation (mutT1) mapped at approximately the same position to the right of leu. Specificity studies showed that the two mutations differ in rates of mutation produced. ..
  41. Chikova A, Schaaper R. Mutator and antimutator effects of the bacteriophage P1 hot gene product. J Bacteriol. 2006;188:5831-8 pubmed
    ..for the Escherichia coli DNA polymerase III theta subunit, as evidenced by its stabilizing effect on certain dnaQ mutants that carry an unstable polymerase III epsilon proofreading subunit (antimutator effect)...
  42. Gupta R, Hamdan S, Dixon N, Sheil M, Beck J. Application of electrospray ionization mass spectrometry to study the hydrophobic interaction between the epsilon and theta subunits of DNA polymerase III. Protein Sci. 2004;13:2878-87 pubmed
  43. Shavitt O, Livneh Z. The beta subunit modulates bypass and termination at UV lesions during in vitro replication with DNA polymerase III holoenzyme of Escherichia coli. J Biol Chem. 1989;264:11275-81 pubmed
    ..Moreover, it predicts that bypass synthesis under SOS conditions might be associated with an altered form of the beta subunit. ..
  44. Woodgate R, Bridges B, Herrera G, Blanco M. Mutagenic DNA repair in Escherichia coli. XIII. Proofreading exonuclease of DNA polymerase III holoenzyme is not operational during UV mutagenesis. Mutat Res. 1987;183:31-7 pubmed
    ..It is concluded that the epsilon proofreading subunit of DNA polymerase III holoenzyme is excluded, inhibited, or inoperative during misincorporation and mutagenesis after UV. ..
  45. Maki H, Horiuchi T, Sekiguchi M. Structure and expression of the dnaQ mutator and the RNase H genes of Escherichia coli: overlap of the promoter regions. Proc Natl Acad Sci U S A. 1983;80:7137-41 pubmed
    ..Escherichia coli chromosome was analyzed by Tn3 transposon insertion and deletion mapping to locate a mutator gene, dnaQ (mutD), and the rnh gene that codes for RNase H...
  46. Livneh Z. Mechanism of replication of ultraviolet-irradiated single-stranded DNA by DNA polymerase III holoenzyme of Escherichia coli. Implications for SOS mutagenesis. J Biol Chem. 1986;261:9526-33 pubmed
    ..Inhibition of the 3'----5' proofreading exonucleolytic activity of the polymerase by dGMP or by a mutD mutation did not increase bypass of pyrimidine photodimers, and neither did purified RecA protein influence the ..
  47. O Donnell M, Kornberg A. Dynamics of DNA polymerase III holoenzyme of Escherichia coli in replication of a multiprimed template. J Biol Chem. 1985;260:12875-83 pubmed
    ..Based on these findings, schemes can be considered for holoenzyme action at the replication fork of a duplex chromosome. ..
  48. Hagensee M, Moses R. Multiple pathways for repair of hydrogen peroxide-induced DNA damage in Escherichia coli. J Bacteriol. 1989;171:991-5 pubmed
    ..One of these pathways would utilize exonuclease III, DNA polymerase III, and DNA polymerase I, while the other would be DNA polymerase I dependent. The RecA protein seems to have little or no direct function in either repair pathway. ..
  49. Reems J, Wood S, McHenry C. Escherichia coli DNA polymerase III holoenzyme subunits alpha, beta, and gamma directly contact the primer-template. J Biol Chem. 1995;270:5606-13 pubmed
    ..These data indicate that assembly of holoenzyme onto a primer-template can occur in distinct stages and results in a structural rearrangement during initiation complex formation. ..
  50. O Donnell M. Replisome architecture and dynamics in Escherichia coli. J Biol Chem. 2006;281:10653-6 pubmed
  51. Nüsslein V, Henke S, Johnston L. Replication of E. coli duplex DNA in vitro. The separation of the DNA containing fractions of a lysate from the soluble enzymes and their complementation properties. Mol Gen Genet. 1976;145:183-90 pubmed
    ..Other factors, that are essential for replicative DNA synthesis, including the dnaG gene product, are washed out of the DNA containing preparations and the system is reconstituted by readdition of the soluble proteins. ..
  52. Foster P, Marinus M. Levels of epsilon, an essential replication subunit of Escherichia coli DNA polymerase III, are controlled by heat shock proteins. J Bacteriol. 1992;174:7509-16 pubmed
    In Escherichia coli, epsilon, the proofreading subunit of DNA polymerase III, is encoded by dnaQ. A random search for mutants that affect the expression of dnaQ revealed that mutations in the genes encoding the heat shock proteins (HSPs) ..
  53. Shwartz H, Livneh Z. Dynamics of termination during in vitro replication of ultraviolet-irradiated DNA with DNA polymerase III holoenzyme of Escherichia coli. J Biol Chem. 1987;262:10518-23 pubmed
    ..We suggest that the inability of the polymerase to bypass photodimers during termination is due to the formation of defective initiation-like complexes with reduced stability at the blocked termini. ..
  54. Fijalkowska I, Schaaper R. Mutants in the Exo I motif of Escherichia coli dnaQ: defective proofreading and inviability due to error catastrophe. Proc Natl Acad Sci U S A. 1996;93:2856-61 pubmed
    The Escherichia coli dnaQ gene encodes the proofreading 3' exonuclease (epsilon subunit) of DNA polymerase III holoenzyme and is a critical determinant of chromosomal replication fidelity...
  55. Iqbal S, Parker G, Davidson H, Moslehi Rahmani E, Robson R. Reversible phase variation in the phnE gene, which is required for phosphonate metabolism in Escherichia coli K-12. J Bacteriol. 2004;186:6118-23 pubmed
    ..All K-12 strains, obtained from collections, appear in the "off" form even when bearing mutations in mutS, mutD, or dnaQ which are known to enhance slip strand events between repetitive sequences...
  56. Nowosielska A, Janion C, Grzesiuk E. Effect of deletion of SOS-induced polymerases, pol II, IV, and V, on spontaneous mutagenesis in Escherichia coli mutD5. Environ Mol Mutagen. 2004;43:226-34 pubmed
    The E. coli dnaQ gene encodes the epsilon subunit of DNA polymerase III (pol III) responsible for the proofreading activity of this polymerase...
  57. Kelman Z, O Donnell M. DNA polymerase III holoenzyme: structure and function of a chromosomal replicating machine. Annu Rev Biochem. 1995;64:171-200 pubmed
    ..This review summarizes our present knowledge about the function of the 10 subunits of this replicating machine and how they coordinate their actions for smooth duplication of chromosomes. ..
  58. Ciesla Z, Jonczyk P, Fijalkowska I. Effect of enhanced synthesis of the epsilon subunit of DNA polymerase III on spontaneous and UV-induced mutagenesis of the Escherichia coli glyU gene. Mol Gen Genet. 1990;221:251-5 pubmed
    ..UV mutagenesis of the glyU gene in Escherichia coli trpA461 (GAG) strains carrying the pIP11 plasmid, in which the dnaQ gene encoding the 3'-5' exonuclease subunit (epsilon) of DNA polymerase III is fused to the tac(trp-lac) promoter...
  59. Suski C, Marians K. Resolution of converging replication forks by RecQ and topoisomerase III. Mol Cell. 2008;30:779-89 pubmed publisher
    ..This resolution reaction is specific for the RecQ-topoisomerase III pair and is mediated by interaction of both of these enzymes with the single-stranded DNA-binding protein SSB. ..
  60. DiFrancesco R, Bhatnagar S, Brown A, Bessman M. The interaction of DNA polymerase III and the product of the Escherichia coli mutator gene, mutD. J Biol Chem. 1984;259:5567-73 pubmed
    ..The decrease in the 3'-single strand exonuclease and turnover indicate a defect in the editing function of the mutD strain, which is at least in part responsible for the high spontaneous mutation rate in mutD...
  61. Pomerantz R, O Donnell M. Replisome mechanics: insights into a twin DNA polymerase machine. Trends Microbiol. 2007;15:156-64 pubmed
    ..These studies demonstrate close similarities between the bacterial and eukaryotic replication machineries. ..
  62. Maki S, Kornberg A. DNA polymerase III holoenzyme of Escherichia coli. II. A novel complex including the gamma subunit essential for processive synthesis. J Biol Chem. 1988;263:6555-60 pubmed
  63. Horiuchi T, Maki H, Maruyama M, Sekiguchi M. Identification of the dnaQ gene product and location of the structural gene for RNase H of Escherichia coli by cloning of the genes. Proc Natl Acad Sci U S A. 1981;78:3770-4 pubmed
    ..The dnaQ+ plasmids consist of a full-length pBR322 DNA and a 1.5-kilobase DNA fragment derived from the E. coli chromosome...
  64. Derose E, Li D, Darden T, Harvey S, Perrino F, Schaaper R, et al. Model for the catalytic domain of the proofreading epsilon subunit of Escherichia coli DNA polymerase III based on NMR structural data. Biochemistry. 2002;41:94-110 pubmed
    ..Nearly all of the residues which have been identified as mutators are located in the portion of the molecule which binds the DNA, with most of these playing either a catalytic or structural role. ..
  65. Quinones A, Kaasch J, Kaasch M, Messer W. Induction of dnaN and dnaQ gene expression in Escherichia coli by alkylation damage to DNA. EMBO J. 1989;8:587-93 pubmed
    The dnaN and dnaQ genes encode the beta-subunit and the epsilon-subunit of the DNA polymerase III holoenzyme...
  66. Toste Rêgo A, Holding A, Kent H, Lamers M. Architecture of the Pol III-clamp-exonuclease complex reveals key roles of the exonuclease subunit in processive DNA synthesis and repair. EMBO J. 2013;32:1334-43 pubmed publisher
  67. Cox E, Gibson T. Selection for high mutation rates in chemostats. Genetics. 1974;77:169-84 pubmed
    ..Fitness values vary between chemostats and are strongly correlated (P < 0.001) with fluctuations in population density. ..
  68. Bressanin D, Stefan A, Piaz F, Cianchetta S, Reggiani L, Hochkoeppler A. Proteolysis of the proofreading subunit controls the assembly of Escherichia coli DNA polymerase III catalytic core. Biochim Biophys Acta. 2009;1794:1606-15 pubmed publisher
    ..Accordingly, the factors catalysing (ClpP, GroL) or preventing (DnaK) this proteolysis exert a crucial checkpoint of the assembly of Escherichia coli DNA polymerase III core. ..
  69. Suzuki E, Kondo T, Makise M, Mima S, Sakamoto K, Tsuchiya T, et al. Alteration in levels of unsaturated fatty acids in mutants of Escherichia coli defective in DNA replication. Biol Pharm Bull. 1998;21:657-61 pubmed
    ..These results suggest that the inhibition of DNA replication causes a lower level of unsaturation of fatty acids in Escherichia coli cells. ..
  70. Takano K, Nakabeppu Y, Maki H, Horiuchi T, Sekiguchi M. Structure and function of dnaQ and mutD mutators of Escherichia coli. Mol Gen Genet. 1986;205:9-13 pubmed
    ..The dnaQ49 mutator has a single base substitution in the dnaQ gene, thus causing one amino acid change, 96Val (GTG)----Gly (GGG), in the DnaQ protein (epsilon subunit of DNA ..
  71. COHEN FIX O, Livneh Z. In vitro UV mutagenesis associated with nucleotide excision-repair gaps in Escherichia coli. J Biol Chem. 1994;269:4953-8 pubmed
    ..Thus, the processivity subunit of the holoenzyme is not required for type II UV mutagenesis, in agreement with a mechanism involving filling-in of short single-stranded DNA gaps. ..
  72. Nakashima N, Tamura T. Conditional gene silencing of multiple genes with antisense RNAs and generation of a mutator strain of Escherichia coli. Nucleic Acids Res. 2009;37:e103 pubmed publisher
    ..Furthermore, when antisense RNAs were targeted to the mutator genes mutS, mutD (dnaQ) and ndk, which are involved in DNA replication or DNA mismatch repair, spontaneous mutation frequencies increased ..
  73. Naufer M, Murison D, Rouzina I, Beuning P, Williams M. Single-molecule mechanochemical characterization of E. coli pol III core catalytic activity. Protein Sci. 2017;26:1413-1426 pubmed publisher
    ..Thus, binding to an unstable primer is the primary mechanism for mismatch recognition during proofreading, rather than an alternative model of duplex defect recognition. ..