Summary
A strain of Escherichia coli K12 harboring simultaneously the temperature-sensitive dnaA46 mutation and a deletion of the trp-topA-cysB region plates with the same full efficiency at 30° C and 42° C. We have analyzed the possible involvement of the gene coding for topoisomerase I, topA, in this suppression phenomenon. The Ts phenotype was retrieved upon introduction of a plasmid-borne DNA fragment including an active topA gene into this strain, but not upon introduction of the same fragment harboring a topA::Tn1000 insertion. Replication seems to remain DnaA-dependent in the Δ(topA) strain, however, since we have been unable to introduce a dnaA::Tn10 allele. We propose either that the dnaA46 gene product is overproduced and compensates for its thermal inactivation, or that initiation at oriC demands less DnaA protein in the absence of topoisomerase I.
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Abbreviations
- Apr :
-
ampicillin resistance
- Cmr :
-
chloramphenicol resistance
- Kmr :
-
Kanamycin resistance
- Str :
-
streptomycin resistance
- Tcr :
-
tetracycline resistance
References
Atlung T (1981) Analysis of seven dnaA suppressor loci in Escherichia coli. In: ICN-UCLA Symposia on Molecular and Cellular Biology XXII. Academic Press, New York, pp 297–314
Bachmann BJ (1983) Linkage map of Escherichia coli K12, Edition 7. Microbiological Reviews 47:180–230
Bagdasarian MM, Isakowska M, Bagdasarian M (1977) Suppression of the DnaA phenotype by mutations in the rpoB cistron of ribonucleic acid polymerase in Salmonella thyphimurium and Escherichia coli. J Bacteriol 130:577–582
Béjar S, Bouché JP (1983) Molecular cloning of the region of the terminus of Escherichia coli K12 DNA replication. J Bacteriol 153:604–609
Bolivar F (1978) Construction and characterization of new cloning vehicles. III. Derivatives of plasmid pBR322 carrying unique EcoRI sites for selection of EcoRI generated recombinant DNA molecules. Gene 4:121–136
Caro L, Berg CM (1971) P1 transduction. In: Grossman L, Moldave K (eds) Methods in enzymology vol XXI. Academic Press, New York, pp 444–458
Clarke L, Carbon J (1976) A colony bank containing synthetic ColEl hybrid plasmids representative of the entire E. coli genome. Cell 9:91–99
DiNardo S, Voelkel KA, Sternglanz R, Reynolds AE, Wright A (1982) Escherichia coli DNA topoisomerase I mutants have compensatory mutations in DNA gyrase genes. Cell 31:43–51
Filutowicz M, Jonczyk P (1981) Essential role of the gyrB gene product in the transcriptional event coupled to dnaA-dependent initiation of Escherichia coli chromosome replication. Mol Gen Genet 183:134–138
Frey J, Chandler M, Caro L (1979) The effects of an Escherichia coli dnaA ts mutation on the replication of the plasmids colEl, pSC101, R100-1 and RTF-TC. Mol Gen Genet 174:117–126
Fuller RS, Kornberg A (1983) Purified dnaA protein in initiation of replication at the Escherichia coli chromosomal origin of replication. Proc Natl Acad Sci USA 80:5817–5821
Fuller RS, Kaguni JM, Kornberg A (1981) Enzymatic replication of the origin of the Escherichia coli chromosome. Proc Natl Acad Sci USA 78:7370–7374
Guyer MS (1978) The γδ sequence of F is an insertion sequence. J Mol Biol 126:347–365
Guyer MS, Reed RR, Steitz JA, Low KB (1980) Identification of a sex-factor-affinity site in E. coli as γδ. Cold Spring harbor Symp Quant Biol 45:135–140
Hansen EB, Hansen FG, von Meyenburg K (1982) The nucleotide sequence of the dnaA gene and the first part of the dnaN gene of Escherichia coli K12. Nucl Acids Res 10:7373–7385
Hirota Y, Mordoh J, Jacob F (1970) On the process of cellular division in Escherichia coli. III Thermosensitive mutants of Escherichia coli altered in the process of DNA intitiation. J Mol Biol 53:369–387
Hirschel BJ, Berg DE (1982) A derivative of Tn5 with direct terminal repeats can transpose. J Mol Biol 155:105–120
Hirschel BJ, Galas DJ, Berg DE, Chandler M (1982) Structure and stability of transposon 5-mediated cointegrates. J Mol Biol 159:557–580
Kellenberger-Gujer G, Podhajska AJ, Caro L (1978) A cold sensitive dnaA mutant of E. coli which overinitiates chromosome replication at low temperature. Mol Gen Genet 162:9–16
Kogoma T, von Meyenburg K (1983) The origin of replication, oriC, and the dnaA protein are dispensable in stable DNA replication (sdrA) mutants of Escherichia coli K12. EMBO Journal 2:463–468
Louarn J, Patte J, Louarn JM (1977) Evidence for a fixed termination site of chromosome replication in Escherichia coli K12. J Mol Biol 115:295–314
Louarn J, Patte J, Louarn JM (1982) Suppression of Escherichia-coli dnaA46 mutations by integration of plasmid R100-1 derivatives: constraints imposed by the replication terminus. J Bacteriol 151:657–667
Low KB (1972) Escherichia coli K12 F-prime factors, old and new. Bacteriol Reviews 36:587–607
Maniatis T, Fritsch EF, Sambrook J (1982) Molecular cloning. A laboratory manual. Cold Spring Harbor Laboratory (ed)
Menzel R, Gellert M (1983) Regulation of the genes for E. coli DNA gyrase: homeostatic control of DNA supercoiling. Cell 34:105–113
Nishimura Y, Caro L, Berg CM, Hirota Y (1971) Chromosome replication in Escherichi coli. IV. Control of chromosome replication and cell division by an integrated episome. J Mol Biol 55:441–456
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
Sakakibara Y, Yuasa S (1982) Continuous synthesis of the dnaA gene product of Escherichia coli in the cell cycle. Mol Gen Genet 186:87–94
Sedmak JJ, Grossberg SE (1977) A rapid, sensitive, and versatile assay for protein using coomassie brilliant blue G250. Analytical Biochem 79:544–552
Sternglanz R, DiNardo S, Voelkel KA, Nishimura Y, Hirota Y, Becherer K, Zumstein L, Wang JC (1981) Mutations in the gene coding for Escherichia coli DNA topoisomerase I affect transcription and transposition. Proc Natl Acad Sci USA 78:2747–2751
Trucksis M, Depew RE (1981) Identification and localization of a gene that specifies production of Escherichia coli DNA topoisomerase I. Proc Natl Acad Sci USA 78:2164–2168
Virolle MJ, Gélugne JP, Béjar S, Bouché JP (1983) Origin of Escherichia coli K12 Hfr B7. J Bacteriol 153:610–615
Wang JC, Becherer K (1983) Cloning of the gene topA encoding for DNA topoisomerase I and the physical mapping of the cysB-topA-trp region of Escherichia coli. Nucl Acids Res 11:1773–1790
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Communicated by W. Arber
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Louarn, J., Bouché, JP., Patte, J. et al. Genetic inactivation of topoisomerase I suppresses a defect in initiation of chromosome replication in Escherichia coli . Mol Gen Genet 195, 170–174 (1984). https://doi.org/10.1007/BF00332741
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DOI: https://doi.org/10.1007/BF00332741