Summary
Two Tn10 insertions that are in the rac locus of the chromosome of Escherichia coli have been isolated and characterized. These insertions are located at min 29.7 and min 30.0. The insertions are stable when an F123 rac::Tn10 episome is transferred to an F- rac + recipient, but they are lost at a high frequency when transferred to an F- rac - recipient. This latter condition has been previously, demonstrated to cause the excision of the rac locus. The Tn10 insertions are also lost at a high frequency when strains containing them are lysogenized with λ reverse. If the lysogens that have lost the Tn10 insertion are subsequently cured of λ reverse, the cells no longer contain sequences homologous with rac locus DNA. These strains were rac - when tested for recombination activation (Low 1973), and this procedure consequently provides a simple means to make isogenic rac - and rac - strains.
Similar content being viewed by others
References
Bachmann BJ (1972) Pedigrees of some mutant strains of Escherichia coli K12. Bacteriol Rev 36:525–557
Bachmann BJ, Low KB (1980) Linkage map of Escherichia coli, edition 6. Microbiol. Rev 44:1–56
Bolivar F, Beckman K (1979) Plasmids of Escherichia coli as cloning vehicles. In: Wu R (ed) Methods in enzymology, vol. 68. Academic Press, New York, pp 248–267
Diaz R, Barnesley P, Pritchard R (1979) Location and characterization of a new replication origin in the E. coli K12 chromosome. Mol Gen Genet 175:151–157
Evans R, Seeley N, Kuempel P (1979) Loss of rac locus DNA in merozygotes of Escherichia coli K12. Mol Gen Genet 175:245–250
Foster TJ (1977) Insertion of the tetracycline-resistance translocation unit Tn10 into the lac operon of E. coli K12. Mol Gen Genet 154:305–309
Gillen JR, Karu, AE, Nagaishi H, Clark AJ (1977) Characterization of the deoxyribonuclease determined by λ reverse as exonuclease VIII of Escherichia coli. J Mol Biol 113:27–41
Gottesman M, Gottesman M, Gottesman S, Gellert M (1974) Characterization of bacteriophage λ reverse as an Escherichia coli phage carrying a unique set of host-derived recombination functions. J Mol Biol 88:471–487
Kaiser K, Murray N (1979) Physical characterisation of the “Rac prophage” in E. coli. K12. Mol Gen Genet 175:159–174
Kaiser K, Murray N (1980) On the nature of the sbcA mutations in E. coli K12. Mol Gen Genet 179:555–563
Kleckner N, Roth J, Botstein D (1977) Genetic engineering in vivo using translocatable drug-resistance elements. J Mol Biol 116:125–159
Kleckner N, Barker D, Ross D, Botstein D (1978) Properties of the translocatable tetracycline-resistance element Tn10 in Escherichia coli and bacteriophage λ. Genetics 90:427–450
Kuempel P, Duerr S (1978) Chromosome replication in Escherichia coli is inhibited in the terminus region near the rac locus. Cold Spring Harbor Symp Quant Biol 43:563–567
Kuempel P, Duerr S, Seeley N (1977) Terminus region of the chromosome of Escherichia coli inhibits replication forks. Proc Natl Acad Sci USA 74:3927–3931
Kushner S, Nagaishi H, Clark AJ (1974) Isolation of exonuclease VIII: the enzyme associated with the sbcA indirect suppressor. Proc Natl Acad Sci USA 71:3593–3597
Lambden PR, Guest JR (1976) Mutants of Escherichia coli K12 unable to use fumarate as an anaerobic electron acceptor. J Gen Microbiol 97:145–160
Lloyd RG, Barbour SD (1974) The genetic location of the sbcA gene of Escherichia coli. Mol Gen Genet 134:157–171
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 (1979) Map location of the replication terminus of the Escherichia coli chromosome. Mol Gen Genet 172:7–11
Low KB (1973) Restoration by the rac locus of recombination forming ability in recB - and recC - merozygotes of Escherichia coli K12. Mol Gen Genet 122:119–130
Miller JH (1972) Experiments in molecular genetics. Cold Spring Harbor Laboratory, New York
Wu T (1966) A model for three-point analysis of random general transduction. Genetics 54:405–410
Author information
Authors and Affiliations
Additional information
Communicated by T. Yura
Rights and permissions
About this article
Cite this article
Binding, R., Romansky, G., Bitner, R. et al. Isolation and properties of Tn10 insertions in the rac locus of Escherichia coli . Molec. Gen. Genet. 183, 333–340 (1981). https://doi.org/10.1007/BF00270637
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00270637