Abstract
Plasmid R68.45 has been useful in promoting the transfer of chromosomal markers in bacteria of many genera. In donors harboring R68.45, chromosome-mobilizing ability (Cma) may be lost without the loss of other plasmid markers. However, Cma can be somewhat stabilized by maintenance of the donors in the presence of kanamycin (Km). We isolated variants of R68.45 from four bacterial species of three genera. Plasmid variants isolated included those without Cma, without transfer function (Tra) and Cma, or without Tra, Cma, and Km resistance. In Erwinia carotovora subsp. atroceptica EA153, the loss of plasmid markers is dependent on the culture medium on which the donors are maintained. Restriction endonuclease analyses of the variant plasmids revealed that most are deletion mutants of R68.45. In all cases when the uncertainty in the ends of the deletions was not too great, one end of the deletion was shown to originate within or near the direct DNA duplication in R68.45 which is required for Cma and which maps close to the Km resistance determinant. Furthermore, the types of deletions observed are consistent with what might be expected for deletions generated by tandemly repeated insertion sequences. Therefore, we suggest that the DNA duplication is the source of much of the instability observed in R68.45. However, data are presented for E. carotovora subsp. atroceptica EA153 which suggest that another region of R68.45 may also play a role in its stability in this species.
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- Barbour S. D., Nagaishi H., Templin A., Clark A. J. Biochemical and genetic studies of recombination proficiency in Escherichia coli. II. Rec+ revertants caused by indirect suppression of rec- mutations. Proc Natl Acad Sci U S A. 1970 Sep;67(1):128–135. doi: 10.1073/pnas.67.1.128. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Barth P. T., Grinter N. J., Bradley D. E. Conjugal transfer system of plasmid RP4: analysis by transposon 7 insertion. J Bacteriol. 1978 Jan;133(1):43–52. doi: 10.1128/jb.133.1.43-52.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burkardt H. J., Riess G., Pühler A. Relationship of group P1 plasmids revealed by heteroduplex experiments: RP1, RP4, R68 and RK2 are identical. J Gen Microbiol. 1979 Oct;114(2):341–348. doi: 10.1099/00221287-114-2-341. [DOI] [PubMed] [Google Scholar]
- Chatterjee A. K. Acceptance by Erwinia spp. of R plasmid R68.45 and its ability to mobilize the chromosome of Erwinia chrysanthemi. J Bacteriol. 1980 Apr;142(1):111–119. doi: 10.1128/jb.142.1.111-119.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eckhardt T. A rapid method for the identification of plasmid desoxyribonucleic acid in bacteria. Plasmid. 1978 Sep;1(4):584–588. doi: 10.1016/0147-619x(78)90016-1. [DOI] [PubMed] [Google Scholar]
- Grinsted J., Bennett P. M., Richmond M. H. A restriction enzyme map of R-plasmid RP1. Plasmid. 1977 Nov;1(1):34–37. doi: 10.1016/0147-619x(77)90006-3. [DOI] [PubMed] [Google Scholar]
- Haas D., Holloway B. W. Chromosome mobilization by the R plasmid R68.45: a tool in Pseudomonas genetics. Mol Gen Genet. 1978 Jan 17;158(3):229–237. doi: 10.1007/BF00267194. [DOI] [PubMed] [Google Scholar]
- Haas D., Holloway B. W. R factor variants with enhanced sex factor activity in Pseudomonas aeruginosa. Mol Gen Genet. 1976 Mar 30;144(3):243–251. doi: 10.1007/BF00341722. [DOI] [PubMed] [Google Scholar]
- Leemans J., Villarroel R., Silva B., Van Montagu M., Schell J. Direct repetition of a 1.2 Md DNA sequence is involved in site-specific recombination by the P1 plasmid R68. Gene. 1980 Sep;10(4):319–328. doi: 10.1016/0378-1119(80)90152-3. [DOI] [PubMed] [Google Scholar]
- Meyer R., Figurski D., Helinski D. R. Physical and genetic studies with restriction endonucleases on the broad host-range plasmid RK2. Mol Gen Genet. 1977 Apr 29;152(3):129–135. doi: 10.1007/BF00268809. [DOI] [PubMed] [Google Scholar]
- Reif H. J., Saedler H. IS1 is involved in deletion formation in the gal region of E. coli K12. Mol Gen Genet. 1975;137(1):17–28. doi: 10.1007/BF00332538. [DOI] [PubMed] [Google Scholar]
- Riess G., Holloway B. W., Pühler A. R68.45, a plasmid with chromosome mobilizing ability (Cma) carries a tandem duplication. Genet Res. 1980 Aug;36(1):99–109. doi: 10.1017/s0016672300019704. [DOI] [PubMed] [Google Scholar]
- Stanisich V. A., Holloway B. W. Chromosome transfer in Pseudomonas aeruginosa mediated by R factors. Genet Res. 1971 Apr;17(2):169–172. doi: 10.1017/s0016672300012179. [DOI] [PubMed] [Google Scholar]
- Starlinger P. IS elements and transposons. Plasmid. 1980 May;3(3):241–259. doi: 10.1016/0147-619x(80)90039-6. [DOI] [PubMed] [Google Scholar]
- Watson J. M., Holloway B. W. Chromosome mapping in Pseudomonas aeruginosa PAT. J Bacteriol. 1978 Mar;133(3):1113–1125. doi: 10.1128/jb.133.3.1113-1125.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Willetts N. S., Crowther C., Holloway B. W. The insertion sequence IS21 of R68.45 and the molecular basis for mobilization of the bacterial chromosome. Plasmid. 1981 Jul;6(1):30–52. doi: 10.1016/0147-619x(81)90052-4. [DOI] [PubMed] [Google Scholar]