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. 1989 Mar;86(6):1771–1775. doi: 10.1073/pnas.86.6.1771

Conjugative transfer of promiscuous IncP plasmids: interaction of plasmid-encoded products with the transfer origin.

J P Fürste 1, W Pansegrau 1, G Ziegelin 1, M Kröger 1, E Lanka 1
PMCID: PMC286786  PMID: 2538813

Abstract

To characterize protein-DNA interactions involved in the initiation of conjugative transfer replication, we isolated and sequenced the transfer origins (oriT) of the promiscuous IncP plasmids RP4 and R751. The central initiating event at the transfer origin of a conjugative plasmid is the cleavage at a unique site (nic) of the strand to be transferred to a recipient cell. This process can be triggered after the assembly of "relaxosomes" (plasmid DNA-protein relaxation complexes), requiring plasmid-encoded gene products. We analyzed the nicking reaction for plasmid RP4 and demonstrated that one of the plasmid strands is specifically cleaved within oriT. The fully functional oriT of RP4 represents an intergenic DNA region of approximately 350 base pairs. Dissection of oriT revealed that a portion carrying nic and symmetric sequence repeats determines oriT specificity. This part of oriT is contiguous to a region that is essential for efficient mobilization of oriT plasmids. In addition, oriT contains potential promoter sites allowing divergent transcription of two operons flanking oriT. We over-produced gene products and, from analyzing the products of defined deletion mutants, deduced the gene arrangements. Formation of RP4 relaxosomes is likely to depend on the presence of at least two plasmid-encoded components, which act in trans. Corresponding genes map on one side of oriT. Purification of the traJ product revealed it to be an 11-kDa polypeptide that binds to oriT DNA in vitro. The protein recognizes the part of oriT that is responsible for oriT specificity.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Biggin M. D., Gibson T. J., Hong G. F. Buffer gradient gels and 35S label as an aid to rapid DNA sequence determination. Proc Natl Acad Sci U S A. 1983 Jul;80(13):3963–3965. doi: 10.1073/pnas.80.13.3963. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Boyer H. W., Roulland-Dussoix D. A complementation analysis of the restriction and modification of DNA in Escherichia coli. J Mol Biol. 1969 May 14;41(3):459–472. doi: 10.1016/0022-2836(69)90288-5. [DOI] [PubMed] [Google Scholar]
  3. Clewell D. B., Helinski D. R. Supercoiled circular DNA-protein complex in Escherichia coli: purification and induced conversion to an opern circular DNA form. Proc Natl Acad Sci U S A. 1969 Apr;62(4):1159–1166. doi: 10.1073/pnas.62.4.1159. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Covarrubias L., Bolivar F. Construction and characterization of new cloning vehicles. VI. Plasmid pBR329, a new derivative of pBR328 lacking the 482-base-pair inverted duplication. Gene. 1982 Jan;17(1):79–89. doi: 10.1016/0378-1119(82)90103-2. [DOI] [PubMed] [Google Scholar]
  5. Datta N., Hedges R. W., Shaw E. J., Sykes R. B., Richmond M. H. Properties of an R factor from Pseudomonas aeruginosa. J Bacteriol. 1971 Dec;108(3):1244–1249. doi: 10.1128/jb.108.3.1244-1249.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Devereux J., Haeberli P., Smithies O. A comprehensive set of sequence analysis programs for the VAX. Nucleic Acids Res. 1984 Jan 11;12(1 Pt 1):387–395. doi: 10.1093/nar/12.1part1.387. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Fürste J. P., Pansegrau W., Frank R., Blöcker H., Scholz P., Bagdasarian M., Lanka E. Molecular cloning of the plasmid RP4 primase region in a multi-host-range tacP expression vector. Gene. 1986;48(1):119–131. doi: 10.1016/0378-1119(86)90358-6. [DOI] [PubMed] [Google Scholar]
  8. Guiney D. G., Helinski D. R. The DNA-protein relaxation complex of the plasmid RK2: location of the site-specific nick in the region of the proposed origin of transfer. Mol Gen Genet. 1979 Oct 3;176(2):183–189. doi: 10.1007/BF00273212. [DOI] [PubMed] [Google Scholar]
  9. Guiney D. G., Yakobson E. Location and nucleotide sequence of the transfer origin of the broad host range plasmid RK2. Proc Natl Acad Sci U S A. 1983 Jun;80(12):3595–3598. doi: 10.1073/pnas.80.12.3595. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Harley C. B., Reynolds R. P. Analysis of E. coli promoter sequences. Nucleic Acids Res. 1987 Mar 11;15(5):2343–2361. doi: 10.1093/nar/15.5.2343. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Jobanputra R. S., Datta N. Trimethoprim R factors in enterobacteria from clinical specimens. J Med Microbiol. 1974 May;7(2):169–177. doi: 10.1099/00222615-7-2-169. [DOI] [PubMed] [Google Scholar]
  12. Lanka E., Lurz R., Fürste J. P. Molecular cloning and mapping of SphI restriction fragments of plasmid RP4. Plasmid. 1983 Nov;10(3):303–307. doi: 10.1016/0147-619x(83)90047-1. [DOI] [PubMed] [Google Scholar]
  13. McDonell M. W., Simon M. N., Studier F. W. Analysis of restriction fragments of T7 DNA and determination of molecular weights by electrophoresis in neutral and alkaline gels. J Mol Biol. 1977 Feb 15;110(1):119–146. doi: 10.1016/s0022-2836(77)80102-2. [DOI] [PubMed] [Google Scholar]
  14. Mizusawa S., Nishimura S., Seela F. Improvement of the dideoxy chain termination method of DNA sequencing by use of deoxy-7-deazaguanosine triphosphate in place of dGTP. Nucleic Acids Res. 1986 Feb 11;14(3):1319–1324. doi: 10.1093/nar/14.3.1319. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Pansegrau W., Lanka E. Conservation of a common 'backbone' in the genetic organization of the IncP plasmids RP4 and R751. Nucleic Acids Res. 1987 Mar 11;15(5):2385–2385. doi: 10.1093/nar/15.5.2385. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Willetts N., Wilkins B. Processing of plasmid DNA during bacterial conjugation. Microbiol Rev. 1984 Mar;48(1):24–41. doi: 10.1128/mr.48.1.24-41.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Yakobson E., Guiney G. Homology in the transfer origins of broad host range IncP plasmids: definition of two subgroups of P plasmids. Mol Gen Genet. 1983;192(3):436–438. doi: 10.1007/BF00392187. [DOI] [PubMed] [Google Scholar]
  19. Yanisch-Perron C., Vieira J., Messing J. Improved M13 phage cloning vectors and host strains: nucleotide sequences of the M13mp18 and pUC19 vectors. Gene. 1985;33(1):103–119. doi: 10.1016/0378-1119(85)90120-9. [DOI] [PubMed] [Google Scholar]

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