Summary
Nucleoid segregation in the Escherichia coli minB mutant and in cells that over-produce minB gene products appeared defective as measured from fluorescence micrographs. Electrophoretic resolution of topoisomers of plasmid isolates from the minB strain revealed a decreased level of negative supercoiling; in addition, multimerization was observed. Over-production of the minB gene product also resulted in a decreased level of negative supercoiling. This phenotype is typical of the gyrB(ts) mutant, which is known to be affected in chromosome decatenation and supercoiling. We propose that the minB mutation and over-production of the minB gene products cause a defect in nucleoid segregation, which may be related to the decrease in negative supercoiling. As in the gyrB(ts) mutant, retardation of nucleoid segregation is proposed to inhibit constriction initiation in the cell centre and to give rise to nucleoid-free cell poles. As a consequence, these cells divide between nucleoid and cell pole, resulting in minicell and (sometimes) in anucleate cell formation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Adler HI, Fisher WD, Cohen A, Hardigee AA (1967) Miniature Escherichia coli cells deficient in DNA. Proc Natl Acad Sci USA 57:321–326
Boer PAJ de, Crossley RE, Rothfield LI (1988) Isolation and characterization of minB, a complex genetic locus involved in correct placement of the division site in Escherichia coli. J Bacteriol 170:2106–2112
Boer PAJ de, Crossley RE, Rothfield LI (1989) A division inhibitor and a topological specificity factor coded for by the minicells locus determine proper placement of the division septum in E. coli. Cell 56:641–649
Chang ACY, Cohen SN (1978) Construction and characterization of amplifiable multicopy DNA cloning vehicles derived from the P15A cryptic miniplasmid. J Bacteriol 134:1141–1156
Cozzarelli N (1980) DNA gyrase and the supercoiling of DNA. Science 207:953–960
Davie E, Sydnor K, Rothfield LI (1984) Genetic basis of minicell formation in Escherichia coli K12. J Bacteriol 158:1202–1203
Dorman CJ, Lynch AS, Ni Bhriain, Higgins CF (1989) DNA supercoiling in Escherichia coli: topA mutations can be suppressed by DNA amplifications involving the tolC locus. Mol Microbiol 3:531–540
Drlica K (1984) Biology of bacterial deoxyribonucleic acid topoisomerases. Microbiol Rev 48:273–289
Drlica K (1987) The nucleoid. In: Neidhardt FC (ed) Escherichia coli and Salmonella typhimurium. ASM Press, Washington, pp 91–103
Drlica K, Pruss GL, Manes SH, Chevalier SG (1986) DNA topoisomerase mutations in bacteria. In: Gualerzi CO, Pon CL (eds) Bacterial chromatin. Springer, Berlin, pp 52–63
Frazer AC, Curtiss R (1975) Production, properties, and utilities of bacterial minicells. Curr Top Immunol Microbiol 69:1–84
Gellert M (1981) DNA topoisomerases. Annu Rev Biochem 50:879–910
Gellert M, Mizuuchi K, O'Dea M, Nash HA (1976) DNA gyrase: enzyme that introduces superhelical turns into DNA. Proc Natl Acad Sci USA 73:3872–3876
Gellert M, Menzel R, Mizuuchi K, O'Dea M, Friedman D (1983) Regulation of DNA supercoiling in E. coli. Cold Spring Harbor Symp Quant Biol 47:763–767
Higgins CF, Dorman CJ, Stirling DA, Waddell L, Booth IR, May G, Bremer E (1988) A physiological role for DNA supercoiling in the osmotic regulation of gene expression in S. typhimurium and E. coli. Cell 52:569–584
Hussain K, Begg KJ, Salmond GPC, Donachie WD (1987) ParD: a new gene coding for a protein required for partitioning and septum localization in Escherichia coli. Mol Microbiol 1:73–81
Irwin CA, Fletcher G, Sills CL, Walker JR (1979) Expression of the Escherichia coli cell division gene sep cloned in a λ charon phage. Science 206:220–222
Jaffé A, D'Ari R, Hiraga S (1988) Minicell forming mutants in Escherichia coli: production of minicells and anucleate rods. J Bacteriol 170:3094–3101
Jones NC, Donachie WD (1973) Chromosome replication, transcription and cell division in Escherichia coli. Nature 243:100–103
Khachatourians GG, Clark DJ, Adler HI, Hardigee AA (1973) Cell growth and division in Escherichia coli: a common genetic control involved in cell division and minicell formation. J Bacteriol 116:226–229
Kleinschmidt AK (1968) Monolayer techniques in electron microscopy of nucleic acid molecules. In: Grossman L, Moldave K (eds) Methods Enzymol 21:361
Kushner S (1978) An improved method for transformation of Escherichia coli with ColE1-derived plasmids. In: Boyer HW, Nicosia S (eds) Genetical engineering. Elsevier, Amsterdam, pp 17–23
Maniatis T, Fritsch EF, Sambrook J (1982) Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York
Miller JH (1972) Experiments in molecular genetics. Cold Spring Harbor, Laboratory, Cold Spring Harbor, New York
Mulder E, Woldringh CL (1989) Actively replicating nucleoids influence the positioning of division sites in Escherichia coli filaments forming cells lacking DNA. J Bacteriol 171:4303–4314
Orr E, Fairweather N, Holland I, Pritchard R (1979) Isolation and characterization of a strain carrying a conditional lethal mutation in the cou gene of Escherichia coli K-12. Mol Gen Genet 177:103–112
Pruss GJ (1985) DNA topoisomerase I mutants: increased heterogeneity in linking number and other replicon-dependent changes in DNA supercoiling. J Mol Biol 185:51–63
Pruss GJ, Manes SH, Drlica K (1982) Escherichia coli DNA topoisomerase I mutants increased supercoiling is corrected by mutations near gyrase genes. Cell 31:35–42
Schaumberg TH, Kuempel PL (1983) Genetic mapping of the minB locus in Escherichia coli K-12. J Bacteriol 153:1063–1065
Steck TR, Drlica K (1984) Bacterial chromosome segregation: evidence for DNA gyrase involvement in decatenation. Cell 36:1081–1088
Taschner PEM, Huls P, Pas E, Woldringh CL (1988) Division behavior and shape changes in isogenic ftsZ, ftsQ, ftsA, pbpB, and ftsE cell division mutants of Escherichia coli during temperature shift experiments. J Bacteriol 170:1533–1540
Teather RM, Collins JF, Donachie WD (1974) Quantal behavior of a diffusible factor which initiates septum formation at potential division sites in Escherichia coli. J Bacteriol 118:407–413
Trueba F, Woldringh CL (1980) Changes in cell diameter during the division cycle of Escherichia coli. J Bacteriol 142:869–878
Wang JC (1985) DNA topoisomerases. Annu Rev Biochem 54:667–679
Author information
Authors and Affiliations
Additional information
Communicated by R. Devoret
Rights and permissions
About this article
Cite this article
Mulder, E., El'Bouhali, M., Pas, E. et al. The Escherichia cohi minB mutation resembles gyrB in defective nucleoid segregation and decreased negative supercoiling of plasmids. Molec. Gen. Genet. 221, 87–93 (1990). https://doi.org/10.1007/BF00280372
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00280372