Analyses of the DNA-binding and transcriptional activation properties of ExsA, the transcriptional activator of the Pseudomonas aeruginosa exoenzyme S regulon
10.1128/jb.177.15.4427-4436.1995
Crossref journal-article
American Society for Microbiology
Journal of Bacteriology (235)
Abstract

ExsA has been implicated as a central regulator of exoenzyme S production by Pseudomonas aeruginosa. In this study, the DNA-binding and transcriptional activation properties of ExsA were investigated. ExsA was produced and purified as a fusion protein, MALA3A2, which was shown to bind specifically to promoter regions that regulated transcription of the exoenzyme S trans-regulatory locus (pC) and a locus located directly downstream of exsA (pD). Previously, MALA3A2 was shown to bind the exoS 5' PstI-NsiI region, which contained two independent but coordinately regulated (ExsA-mediated) promoters, pS' (now termed pORF1) and pS. DNase I footprint analysis of the promoter regions bound by ExsA revealed a common protected consensus sequence of TXAAAAXA. The consensus sequence was located -51 to -52 bp upstream of the transcriptional start sites for pD, pS, and pORF1. Promoter fusion, DNA-binding, and mutagenesis analysis indicated that the consensus sequence was important for transcriptional activation. Each ExsA-controlled promoter region contained at least two consensus sites in close proximity, similar to the arrangement of half-sites seen in AraC-controlled (Escherichia coli) or VirF-controlled (Yersinia enterocolitica) promoters. However, the results of this study suggested that only one consensus site was required in the exoenzyme S (pS) or ORF1 promoter (pORF1) to initiate transcription. These data suggest that members of the exoenzyme S regulon can be defined as possessing an ExsA consensus element which maps at bp -51 or -52 relative to the transcriptional start site.

Bibliography

Hovey, A. K., & Frank, D. W. (1995). Analyses of the DNA-binding and transcriptional activation properties of ExsA, the transcriptional activator of the Pseudomonas aeruginosa exoenzyme S regulon. Journal of Bacteriology, 177(15), 4427–4436.

Authors 2
  1. A K Hovey (first)
  2. D W Frank (additional)
References 55 Referenced 115
  1. Benson , S. A. 1984 . A rapid procedure for isolation of DNA fragments from agarose gels . BioTechniques 2 : 66 - 67 . / BioTechniques / A rapid procedure for isolation of DNA fragments from agarose gels by Benson S. A. (1984)
  2. Bjorn , M. J. , O. R. Pavlovskis , M. R. Thompson , and B. H. Iglewski . 1979 . Production of exoenzyme S during Pseudomonas aeruginosa infection of burned mice . Infect. Immun. 24 : 837 - 842 . (10.1128/iai.24.3.837-842.1979) / Infect. Immun. / Production of exoenzyme S during Pseudomonas aeruginosa infection of burned mice by Bjorn M. J. (1979)
  3. Bodey , G. P. , R. Bolivar , V. Fainstein , and L. Jadeja . 1983 . Infections caused by Pseudomonas aeruginosa . Rev. Infect. Dis. 5 : 279 - 313 . (10.1093/clinids/5.2.279) / Rev. Infect. Dis. / Infections caused by Pseudomonas aeruginosa by Bodey G. P. (1983)
  4. Brubaker , R. R. 1983 . The VWa virulence factor of Yersinia: the molecular basis of the attendant nutritional requirement for Ca2~ . Rev. Infect. Dis. 5 : S748 - S758 . (10.1093/clinids/5.Supplement_4.S748) / Rev. Infect. Dis. / The VWa virulence factor of Yersinia: the molecular basis of the attendant nutritional requirement for Ca2~ by Brubaker R. R. (1983)
  5. Carra , J. H. , and R. Schlief . 1993 . Variation of half-site organization and DNA looping by AraC protein . EMBO J. 12 : 35 - 44 . (10.1002/j.1460-2075.1993.tb05629.x) / EMBO J. / Variation of half-site organization and DNA looping by AraC protein by Carra J. H. (1993)
  6. Coburn , J. 1992 . Pseudomonas aeruginosa exoenzyme S . Curr. Top. Microbiol. Immunol. 175 : 133 - 143 . / Curr. Top. Microbiol. Immunol. / Pseudomonas aeruginosa exoenzyme S by Coburn J. (1992)
  7. Coburn , J. , S. T. Dillon , B. H. Iglewski , and D. M. Gill . 1989 . Exoenzyme S of Pseudomonas aeruginosa ADP-ribosylates the intermediate filament protein vimentin . Infect. Immun. 57 : 996 - 998 . (10.1128/iai.57.3.996-998.1989) / Infect. Immun. / Exoenzyme S of Pseudomonas aeruginosa ADP-ribosylates the intermediate filament protein vimentin by Coburn J. (1989)
  8. Coburn , J. , and D. M. Gill . 1991 . ADP-ribosylation of p21ras and related proteins by Pseudomonas aeruginosa exoenzyme S . Infect. Immun. 59 : 4259 - 4262 . (10.1128/iai.59.11.4259-4262.1991) / Infect. Immun. / ADP-ribosylation of p21ras and related proteins by Pseudomonas aeruginosa exoenzyme S by Coburn J. (1991)
  9. Coburn , J. , A. V. Kane , L. Feig , and D. M. Gill . 1991 . Pseudomonas aeruginosa exoenzyme S requires a eukaryotic protein for ADP-ribosyltransferase activity . J. Biol. Chem. 266 : 6438 - 6446 . (10.1016/S0021-9258(18)38137-7) / J. Biol. Chem. / Pseudomonas aeruginosa exoenzyme S requires a eukaryotic protein for ADP-ribosyltransferase activity by Coburn J. (1991)
  10. Cornelis , G. , C. Sluiters , C. Lambert de Rouvroit , and T. Michiels . 1989 . Homology between VirF, the transcriptional activator of the Yersinia virulence regulon, and AraC, the Escherichia coli arabinose operon regulator . J. Bacteriol. 171 : 254 - 262 . (10.1128/jb.171.1.254-262.1989) / J. Bacteriol. / Homology between VirF, the transcriptional activator of the Yersinia virulence regulon, and AraC, the Escherichia coli arabinose operon regulator by Cornelis G. (1989)
  11. Dunn , T. M. , and R. Schlief . 1984 . Deletion analysis of the Escherichia coli ara PC and PBAD promoters . J. Mol. Biol. 180 : 201 - 204 . (10.1016/0022-2836(84)90437-6) / J. Mol. Biol. / Deletion analysis of the Escherichia coli ara PC and PBAD promoters by Dunn T. M. (1984)
  12. Farinha , M. A. , and A. M. Kropinski . 1989 . Construction of broad-hostrange vectors for general cloning and promoter selection in Pseudomonas and Escherichia coli . Gene 77 : 205 - 210 . (10.1016/0378-1119(89)90068-1) / Gene / Construction of broad-hostrange vectors for general cloning and promoter selection in Pseudomonas and Escherichia coli by Farinha M. A. (1989)
  13. Frank , D. W. , and B. H. Iglewski . 1991 . Cloning and sequence analysis of a trans-regulatory locus required for exoenzyme S synthesis in Pseudomonas aeruginosa . J. Bacteriol. 173 : 6460 - 6468 . (10.1128/jb.173.20.6460-6468.1991) / J. Bacteriol. / Cloning and sequence analysis of a trans-regulatory locus required for exoenzyme S synthesis in Pseudomonas aeruginosa by Frank D. W. (1991)
  14. Frank , D. W. , G. Nair , and H. P. Schweizer . 1994 . Construction and characterization of chromosomal insertional mutations of the Pseudomonas aeruginosa exoenzyme S trans-regulatory locus . Infect. Immun. 62 : 554 - 563 . (10.1128/iai.62.2.554-563.1994) / Infect. Immun. / Construction and characterization of chromosomal insertional mutations of the Pseudomonas aeruginosa exoenzyme S trans-regulatory locus by Frank D. W. (1994)
  15. Fu , H. , J. Coburn , and R. J. Collier . 1993 . The eukaryotic host factor that activates exoenzyme S of Pseudomonas aeruginosa is a member of the 14-3-3 protein family . Proc. Natl. Acad. Sci. USA 90 : 2320 - 2324 . (10.1073/pnas.90.6.2320) / Proc. Natl. Acad. Sci. USA / The eukaryotic host factor that activates exoenzyme S of Pseudomonas aeruginosa is a member of the 14-3-3 protein family by Fu H. (1993)
  16. Gallegos , M. - T. , C. Michán , and J. L. Ramos . 1993 . The XylS/AraC family of regulators . Nucleic Acids Res. 21 : 807 - 810 . (10.1093/nar/21.4.807) / Nucleic Acids Res. / The XylS/AraC family of regulators by Gallegos M. (1993)
  17. Guan , K. L. , and J. E. Dixon . 1990 . Protein tyrosine phosphatase activity of an essential virulence determinant in Yersinia . Science 249 : 553 - 556 . (10.1126/science.2166336) / Science / Protein tyrosine phosphatase activity of an essential virulence determinant in Yersinia by Guan K. L. (1990)
  18. Hanahan , D. 1983 . Studies on transformation of Escherichia coli with plasmids . J. Mol. Biol. 166 : 557 - 580 . (10.1016/S0022-2836(83)80284-8) / J. Mol. Biol. / Studies on transformation of Escherichia coli with plasmids by Hanahan D. (1983)
  19. Harrison , S. C. , and A. K. Aggarwal . 1990 . DNA recognition by proteins with the helix-turn-helix motif. Annu . Rev. Biochem. 59 : 933 - 969 . (10.1146/annurev.bi.59.070190.004441) / Rev. Biochem. / DNA recognition by proteins with the helix-turn-helix motif. Annu by Harrison S. C. (1990)
  20. Hoe , N. P. , and J. D. Goguen . 1993 . Temperature sensing in Yersinia pestis: translation of the LcrF activator protein is thermally regulated . J. Bacteriol. 175 : 7901 - 7909 . (10.1128/jb.175.24.7901-7909.1993) / J. Bacteriol. / Temperature sensing in Yersinia pestis: translation of the LcrF activator protein is thermally regulated by Hoe N. P. (1993)
  21. Hoe , N. P. , F. C. Minion , and J. D. Goguen . 1992 . Temperature sensing in Yersinia pestis: regulation of yopE transcription by lcrF . J. Bacteriol. 174 : 4275 - 4286 . (10.1128/jb.174.13.4275-4286.1992) / J. Bacteriol. / Temperature sensing in Yersinia pestis: regulation of yopE transcription by lcrF by Hoe N. P. (1992)
  22. Iglewski , B. H. , J. Sadoff , M. J. Bjorn , and E. S. Maxwell . 1978 . Pseudomonas aeruginosa exoenzyme S: an adenosine diphosphate ribosyltransferase distinct from toxin A . Proc. Natl. Acad. Sci. USA 75 : 3211 - 3215 . (10.1073/pnas.75.7.3211) / Proc. Natl. Acad. Sci. USA / Pseudomonas aeruginosa exoenzyme S: an adenosine diphosphate ribosyltransferase distinct from toxin A by Iglewski B. H. (1978)
  23. Ishihama , A. 1993 . Protein-protein communication within the transcription apparatus . J. Bacteriol. 175 : 2483 - 2489 . (10.1128/jb.175.9.2483-2489.1993) / J. Bacteriol. / Protein-protein communication within the transcription apparatus by Ishihama A. (1993)
  24. Kulich , S. M. , D. W. Frank , and J. T. Barbieri . 1993 . Purification and characterization of exoenzyme S from Pseudomonas aeruginosa 388 . Infect. Immun. 61 : 307 - 313 . (10.1128/iai.61.1.307-313.1993) / Infect. Immun. / Purification and characterization of exoenzyme S from Pseudomonas aeruginosa 388 by Kulich S. M. (1993)
  25. Kulich , S. M. , D. W. Frank , and J. T. Barbieri . 1995 . Expression of recombinant exoenzyme S of Pseudomonas aeruginosa . Infect. Immun. 63 : 1 - 8 . (10.1128/iai.63.1.1-8.1995) / Infect. Immun. / Expression of recombinant exoenzyme S of Pseudomonas aeruginosa by Kulich S. M. (1995)
  26. Kulich , S. M. , T. L. Yahr , L. M. Mende-Mueller , J. T. Barbieri , and D. W. Frank . 1994 . Cloning the structural gene for the 49-kDa form of exoenzyme S (exoS) from Pseudomonas aeruginosa strain 388 . J. Biol. Chem. 269 : 10431 - 10437 . (10.1016/S0021-9258(17)34078-4) / J. Biol. Chem. / Cloning the structural gene for the 49-kDa form of exoenzyme S (exoS) from Pseudomonas aeruginosa strain 388 by Kulich S. M. (1994)
  27. Lambert de Rouvroit , C. , C. Sluiters , and G. R. Cornelis . 1992 . Role of the transcriptional activator, VirF, and temperature in the expression of the pYV plasmid genes of Yersinia enterocolitica . Mol. Microbiol. 6 : 395 - 409 . (10.1111/j.1365-2958.1992.tb01483.x) / Mol. Microbiol. / Role of the transcriptional activator, VirF, and temperature in the expression of the pYV plasmid genes of Yersinia enterocolitica by Lambert de Rouvroit C. (1992)
  28. Lee , N. , C. Francklyn , and E. P. Hamilton . 1987 . Arabinose-induced binding of AraC protein to araI2 activates the araBAD operon promoter . Proc. Natl. Acad. Sci. USA 84 : 8814 - 8818 . (10.1073/pnas.84.24.8814) / Proc. Natl. Acad. Sci. USA / Arabinose-induced binding of AraC protein to araI2 activates the araBAD operon promoter by Lee N. (1987)
  29. Lowry , O. H. , N. J. Rosebrough , A. L. Farr , and R. J. Randall . 1951 . Protein measurement with the Folin phenol reagent . J. Biol. Chem. 193 : 265 - 275 . (10.1016/S0021-9258(19)52451-6) / J. Biol. Chem. / Protein measurement with the Folin phenol reagent by Lowry O. H. (1951)
  30. Maxam , A. M. , and W. Gilbert . 1977 . A new method for sequencing DNA . Proc. Natl. Acad. Sci. USA 74 : 560 - 564 . (10.1073/pnas.74.2.560) / Proc. Natl. Acad. Sci. USA / A new method for sequencing DNA by Maxam A. M. (1977)
  31. McClure , W. R. 1985 . Mechanism and control of transcription initiation in prokaryotes. Annu . Rev. Biochem. 54 : 171 - 204 . (10.1146/annurev.bi.54.070185.001131) / Rev. Biochem. / Mechanism and control of transcription initiation in prokaryotes. Annu by McClure W. R. (1985)
  32. Neumann , J. R. , C. A. Morency , and K. O. Russian . 1987 . A novel rapid assay for chloramphenicol acetyltransferase gene expression . BioTechniques 5 : 444 - 448 . / BioTechniques / A novel rapid assay for chloramphenicol acetyltransferase gene expression by Neumann J. R. (1987)
  33. Nicas , T. I. , J. Bradley , J. E. Lochner , and B. H. Iglewski . 1985 . The role of exoenzyme S in infections with Pseudomonas aeruginosa . J. Infect. Dis. 152 : 716 - 721 . (10.1093/infdis/152.4.716) / J. Infect. Dis. / The role of exoenzyme S in infections with Pseudomonas aeruginosa by Nicas T. I. (1985)
  34. Nicas , T. I. , and B. H. Iglewski . 1984 . Isolation and characterization of transposon-induced mutants of Pseudomonas aeruginosa deficient in production of exoenzyme S . Infect. Immun. 45 : 470 - 474 . (10.1128/iai.45.2.470-474.1984) / Infect. Immun. / Isolation and characterization of transposon-induced mutants of Pseudomonas aeruginosa deficient in production of exoenzyme S by Nicas T. I. (1984)
  35. Nicas , T. I. , and B. H. Iglewski . 1985 . Contribution of exoenzyme S to the virulence of Pseudomonas aeruginosa . Antibiot. Chemother. (Basel) 36 : 40 - 48 . (10.1159/000410470) / Antibiot. Chemother. (Basel) / Contribution of exoenzyme S to the virulence of Pseudomonas aeruginosa by Nicas T. I. (1985)
  36. Nicas , T. I. , and B. H. Iglewski . 1985 . The contribution of exoproducts to virulence of Pseudomonas aeruginosa . Can. J. Microbiol. 31 : 387 - 392 . (10.1139/m85-074) / Can. J. Microbiol. / The contribution of exoproducts to virulence of Pseudomonas aeruginosa by Nicas T. I. (1985)
  37. Olsen , R. H. , G. Debusscher , and W. R. McCombie . 1982 . Development of broad-host-range vectors and gene banks: self-cloning of the Pseudomonas aeruginosa PAO chromosome . J. Bacteriol. 150 : 60 - 69 . (10.1128/jb.150.1.60-69.1982) / J. Bacteriol. / Development of broad-host-range vectors and gene banks: self-cloning of the Pseudomonas aeruginosa PAO chromosome by Olsen R. H. (1982)
  38. Reeder , T. , and R. Schlief . 1993 . AraC protein can activate transcription from only one position and when pointed in only one direction . J. Mol. Biol. 231 : 205 - 218 . (10.1006/jmbi.1993.1276) / J. Mol. Biol. / AraC protein can activate transcription from only one position and when pointed in only one direction by Reeder T. (1993)
  39. Rosqvist , R. , I. Bölin , and H. Wolf-Watz . 1988 . Inhibition of phagocytosis in Yersinia pseudotuberculosis: a virulence plasmid-encoded ability involving the Yop2b protein . Infect. Immun. 56 : 2139 - 2143 . (10.1128/iai.56.8.2139-2143.1988) / Infect. Immun. / Inhibition of phagocytosis in Yersinia pseudotuberculosis: a virulence plasmid-encoded ability involving the Yop2b protein by Rosqvist R. (1988)
  40. Rosqvist , R. , Å. Forsberg, M. Rimpiläinen , T. Bergman , and H. Wolf-Watz . 1990 . The cytotoxic protein YopE of Yersiniae obstructs the primary host defense . Mol. Microbiol. 4 : 657 - 667 . (10.1111/j.1365-2958.1990.tb00635.x) / Mol. Microbiol. / The cytotoxic protein YopE of Yersiniae obstructs the primary host defense by Rosqvist R. (1990)
  41. Rosqvist , R. , Å. Forsberg, and H. Wolf-Watz . 1991 . Intracellular targeting of the Yersinia YopE cytotoxin in mammalian cells induces actin microfilament disruption . Infect. Immun. 59 : 4562 - 4569 . (10.1128/iai.59.12.4562-4569.1991) / Infect. Immun. / Intracellular targeting of the Yersinia YopE cytotoxin in mammalian cells induces actin microfilament disruption by Rosqvist R. (1991)
  42. Sambrook J. E. F. Fritsch and T. Maniatis. 1989. Molecular cloning: a laboratory manual 2nd ed. Cold Spring Harbor Laboratory Press Cold Spring Harbor N.Y.
  43. Sanger , F. , S. Nicklen , and A. R. Coulson . 1977 . DNA sequencing with chain-terminating inhibitors . Proc. Natl. Acad. Sci. USA 74 : 5463 - 5467 . (10.1073/pnas.74.12.5463) / Proc. Natl. Acad. Sci. USA / DNA sequencing with chain-terminating inhibitors by Sanger F. (1977)
  44. Straley , S. , and W. S. Bowmer . 1986 . Virulence genes regulated at the transcriptional level of Ca2~ in Yersinia pestis include structural genes for outer membrane proteins . Infect. Immun. 51 : 445 - 454 . (10.1128/iai.51.2.445-454.1986) / Infect. Immun. / Virulence genes regulated at the transcriptional level of Ca2~ in Yersinia pestis include structural genes for outer membrane proteins by Straley S. (1986)
  45. Straley , S. , G. V. Plano , E. Skrzypek , P. L. Haddix , and K. A. Fields . 1993 . Regulation by Ca~2 in the Yersinia low-Ca~2 response . Mol. Microbiol. 8 : 1005 - 1010 . (10.1111/j.1365-2958.1993.tb01644.x) / Mol. Microbiol. / Regulation by Ca~2 in the Yersinia low-Ca~2 response by Straley S. (1993)
  46. Straley , S. C. , E. Skrzypek , G. V. Plano , and J. B. Bliska . 1993 . Yops of Yersinia spp. pathogenic for humans . Infect. Immun. 61 : 3105 - 3110 . (10.1128/iai.61.8.3105-3110.1993) / Infect. Immun. / Yops of Yersinia spp. pathogenic for humans by Straley S. C. (1993)
  47. Tabor , S. , and C. Richardson . 1985 . A bacteriophage T7 RNA polymerase/ promoter system for controlled exclusive expression of specific genes . Proc. Natl. Acad. Sci. USA 82 : 1074 - 1078 . (10.1073/pnas.82.4.1074) / Proc. Natl. Acad. Sci. USA / A bacteriophage T7 RNA polymerase/ promoter system for controlled exclusive expression of specific genes by Tabor S. (1985)
  48. Taylor , J. W. , J. Ott , and F. Eckstein . 1986 . The rapid generation of oligonucleotide-directed mutations at high frequency using phosphorothioatemodified DNA . Nucleic Acids Res. 13 : 8764 - 8785 . / Nucleic Acids Res. / The rapid generation of oligonucleotide-directed mutations at high frequency using phosphorothioatemodified DNA by Taylor J. W. (1986)
  49. Thompson M. R. M. J. Bjorn P. A. Sokol J. D. Lile and B. H. Iglewski. 1980. Exoenzyme S: an ADP-ribosyl transferase produced by Pseudomonas aeruginosa p. 425-433. In M. Smulson and T. Sugimura (ed.) Novel ADPribosylations of regulatory enzymes and proteins. Elsevier North-Holland Inc. Amsterdam.
  50. Vogel , H. J. , and D. M. Bonner . 1956 . Acetylornithinase of Escherichia coli: partial purification and some properties . J. Biol. Chem. 218 : 97 - 106 . (10.1016/S0021-9258(18)65874-0) / J. Biol. Chem. / Acetylornithinase of Escherichia coli: partial purification and some properties by Vogel H. J. (1956)
  51. Wattiau , P. , and G. R. Cornelis . 1993 . SycE, a chaperone-like protein of Yersinia enterocolitica involved in the secretion of YopE . Mol. Microbiol. 8 : 123 - 131 . (10.1111/j.1365-2958.1993.tb01209.x) / Mol. Microbiol. / SycE, a chaperone-like protein of Yersinia enterocolitica involved in the secretion of YopE by Wattiau P. (1993)
  52. Wattiau , P. , and G. R. Cornelis . 1994 . Identification of DNA sequences recognized by VirF, the transcriptional activator of the Yersinia yop regulon . J. Bacteriol. 176 : 3878 - 3884 . (10.1128/jb.176.13.3878-3884.1994) / J. Bacteriol. / Identification of DNA sequences recognized by VirF, the transcriptional activator of the Yersinia yop regulon by Wattiau P. (1994)
  53. Yahr , T. L. , and D. W. Frank . 1994 . Transcriptional organization of the trans-regulatory locus which controls exoenzyme S synthesis in Pseudomonas aeruginosa . J. Bacteriol. 176 : 3832 - 3838 . (10.1128/jb.176.13.3832-3838.1994) / J. Bacteriol. / Transcriptional organization of the trans-regulatory locus which controls exoenzyme S synthesis in Pseudomonas aeruginosa by Yahr T. L. (1994)
  54. .Yahr T. L. and D. W. Frank. Unpublished data.
  55. Yahr , T. L. , A. K. Hovey , S. M. Kulich , and D. W. Frank . 1995 . Transcriptional analysis of the Pseudomonas aeruginosa exoenzyme S structural gene . J. Bacteriol. 177 : 1169 - 1178 . (10.1128/jb.177.5.1169-1178.1995) / J. Bacteriol. / Transcriptional analysis of the Pseudomonas aeruginosa exoenzyme S structural gene by Yahr T. L. (1995)
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Created 8 years, 9 months ago (Nov. 9, 2016, 9:04 a.m.)
Deposited 4 years, 1 month ago (July 29, 2021, 1:50 p.m.)
Indexed 1 month, 4 weeks ago (July 4, 2025, 2:13 a.m.)
Issued 30 years, 1 month ago (Aug. 1, 1995)
Published 30 years, 1 month ago (Aug. 1, 1995)
Published Print 30 years, 1 month ago (Aug. 1, 1995)
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@article{Hovey_1995, title={Analyses of the DNA-binding and transcriptional activation properties of ExsA, the transcriptional activator of the Pseudomonas aeruginosa exoenzyme S regulon}, volume={177}, ISSN={1098-5530}, url={http://dx.doi.org/10.1128/jb.177.15.4427-4436.1995}, DOI={10.1128/jb.177.15.4427-4436.1995}, number={15}, journal={Journal of Bacteriology}, publisher={American Society for Microbiology}, author={Hovey, A K and Frank, D W}, year={1995}, month=aug, pages={4427–4436} }