Summary
Previous results (Baumberg and Lovett 1977) showed that many conjugative plasmids, most notably those of the IncFII group, were only transferable to Escherichia coli K12 rho mutants at very low frequencies, and that this appeared to be due to a lethal interaction between plasmid and rho - allele. Experiments reported here were designed to examine this phenomenon further, and in particular to test the possibility that uncontrolled plasmid replication in the presence of the rho mutant allele occurs. The rifampicin resistance allele rpo203 antagonizes the effect of rho201 on conjugal plasmid transfer; since the former is known to counteract the latter's effect on transcription termination, this result indicates that the plasmid-rho interaction stems directly from the lack of transcription termination caused by a rho mutant allele. Direct estimation of Rldrd19 replication after conjugal transfer to rho + and rho201 recipients showed no difference according to rho status. Also, cotransduction of rho101 and 201 with ilv:: Tn5 into recipients carrying miniplasmid derivatives of R1, which retain a restriction fragment containing all the DNA known to be involved in plasmid replication, was normal and the rho - transductants retained the miniplasmids. It therefore appears that the lethal interaction between the Inc FII plasmids and rho mutant alleles does not involve plasmid replication functions.
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References
Baumberg S, Lovett MG (1977) Reduced recovery of plasmid transconjugants in crosses with Escherichia coli rho mutant recipients. Plasmid 1:118–122
Beard JP, Connolly JC (1975) Detection of a protein, similar to the sex pilus subunit, in the outer membrane of Escherichia coli cells carrying a derepressed F-like R-factor. J Bacteriol 122:59–65
Casadaban MJ, Cohen SN (1980) Analysis of gene control signals by DNA fusion and cloning in Escherichia coli. J Mol Biol 138:179–207
Clark DJ, Maaløe O (1967) DNA replication and the cell cycle in Escherichia coli. J Mol Biol 23:99–112
Das A, Court D, Adhya S (1976) Conditional lethal mutants of Escherichia coli defective in transcription termination factor rho. Proc Natl Acad Sci USA 73:1959–1963
Das A, Merril C, Adhya S (1978) Interaction of RNA polymerase and rho in transcription termination: coupled ATPase. Proc Natl Acad Sci USA 75:4828–4832
Guarente LP, Mitchell DH, Beckwith J (1977) Transcription termination at the end of the tryptophan operon of Escherichia coli. J Mol Biol 112:423–436
Guarente LP, Beckwith J (1978) Mutant RNA polymerase of Escherichia coli terminates transcription in strains making defective rho factor. Proc Natl Acad Sci USA 75:294–297
Korn LJ, Yanofsky C (1976a) Polarity suppressors increase expression of the wild-type tryptophan operon of Escherichia coli. J Mol Biol 103:395–409
Korn LJ, Yanofsky C (1976b) Polarity suppressors defective in transcription termination at the attenuator of the tryptophan operon of Escherichia coli have altered rho factor. J Mol Biol 106:231–241
Lennox ES (1955) Transduction of linked genetic characters of the host by bacteriophage Pl. Virology: 190–206
Light J, Molin S (1981) Replication control functions of plasmid Rl act as inhibitors of expression of a gene required for replication. Mol Gen Genet 184:56–61
Molin S, Stougaard P, Uhlin BE, Gustafsson P, Nordström K (1979) Clustering of genes involved replication, incompatibility, and stable maintenance of the resistance plasmid Rldrd-19. J Bacteriol 138:70–79
Richardson JP, Grimley C, Lowery C (1975) Transcription termination factor rho activity is altered in Escherichia coli with suA gene mutations. Proc Natl Acad Sci USA 72:1725–1728
Roberts JW (1969) Termination factor for RNA synthesis. Nature 224:1168–1174
Rosen J, Ryder T, Ohtsubo H, Ohtsubo E (1981) Role of RNA transcripts in replication, incompatibility and copy number control in antibiotic resistance plasmid derivatives. Nature 290:794–797
Stougaard P, Molin S (1981) Vertical dye-buoyant density gradients for rapid analysis and preparation of plasmid DNA. Anal Biochem 118:191–193
Stougaard P, Molin S, Nordström K (1981) RNAs involved in copy-number control and incompatibility of plasmid Rl. Proc Natl Acad Sci USA 78:6008–60012
Stougaard P, Light J, Molin S (1982) Convergent transcription interferes with expression of the copy number control gene copA from plasmid Rl. EMBO Journal 1:323–328
Uhlin BE, Nordström K (1975) Plasmid incompatibility and control of replication: copy mutants of the R-factor Rl in Escherichia coli K-12. J Bacteriol 124:641–649
Willetts NS, Skurray RA (1980) The conjugation system of F-like plasmids. Ann Rev Genet 14:41–76
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Communicated by D. Goldfarb
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Light, J., Baumberg, S. Further studies on the inviability of Escherichia coliK12 rho mutant strains carrying IncFII plasmids. Molec Gen Genet 189, 309–313 (1983). https://doi.org/10.1007/BF00337822
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DOI: https://doi.org/10.1007/BF00337822