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PMID: 6378626 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

The korB gene of broad host range plasmid RK2 is a major copy number control element which may act together with trfB by limiting trfA expression.

The EMBO journal ·Vol. 3 ·No. 7 ·1984-07-00 ·Pages 1513-9

Thomas CM, Hussain AA

Abstract

For replication, plasmid RK2 encodes a vegetative replication origin, oriV RK2, and a gene, trfA, whose polypeptide product(s) is essential for oriV RK2 activity. The trfA gene is transcribed as part of a polycistronic operon which also includes kilD. Transcription of this operon is negatively regulated by the products of the trfB/korD/korA and korB loci. Mini replicons previously studied in detail lack the korB locus and have copy numbers significantly higher than RK2 itself. Here we report that korB in trans expresses incompatibility towards RK2 replicons either when the korB gene dosage is high or when it is expressed from a strong foreign promoter. This incompatibility can be largely overcome if a trfA gene which is expressed from a foreign promoter, and is therefore not regulated by korB, is supplied in trans. When korB is introduced in cis to mini RK2 replicons the copy number is reduced to within the range estimated for parental RK2. Deletions in the oriV RK2 region which otherwise cause quite large increases in plasmid copy number have only a small effect when korB is present in cis. These results suggest that korB in combination with trfB may be the overriding copy number control element in RK2 reducing trfA expression to levels limiting for replication.

MeSH Terms
Bacterial Proteins/genetics DNA Replication DNA, Bacterial/genetics Escherichia coli/genetics Gene Expression Regulation Genes, Bacterial Plasmids Transcription, Genetic
Chemicals
Bacterial Proteins DNA, Bacterial
Authors & Affiliations
2 authors, click to expand affiliations / ORCID
Thomas C M
Hussain A A
References (36)
36 references, click to expand
  1. Construction and characterization of new cloning vehicles. II. A multipurpose cloning system.
    Gene. 1977;2(2):95-113 PMID: 344137
  2. Conjugal transfer system of plasmid RP4: analysis by transposon 7 insertion.
    J Bacteriol. 1978 Jan;133(1):43-52 PMID: 338595
  3. Replication of an origin-containing derivative of plasmid RK2 dependent on a plasmid function provided in trans.
    Proc Natl Acad Sci U S A. 1979 Apr;76(4):1648-52 PMID: 377280
  4. Regions of broad-host-range plasmid RK2 which are essential for replication and maintenance.
    J Bacteriol. 1980 Jan;141(1):213-22 PMID: 6243621
  5. 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):183-9 PMID: 393953
  6. Suppression of Co1E1 replication properties by the Inc P-1 plasmid RK2 in hybrid plasmids constructed in vitro.
    J Mol Biol. 1979 Sep 25;133(3):295-318 PMID: 395312
  7. Expression of incompatibility by derivatives of the broad host-range inc P-1 plasmid RK2.
    Mol Gen Genet. 1979;177(1):155-61 PMID: 395412
  8. Relationship of group P1 plasmids revealed by heteroduplex experiments: RP1, RP4, R68 and RK2 are identical.
    J Gen Microbiol. 1979 Oct;114(2):341-8 PMID: 120408
  9. Plasmid cloning vehicles derived from plasmids ColE1, F, R6K, and RK2.
    Methods Enzymol. 1979;68:268-80 PMID: 232215
  10. Replication and incompatibility properties of segments of the origin region of replication of the broad host range plasmid RK2.
    Mol Gen Genet. 1981;181(1):1-7 PMID: 6261080
  11. Isolation and characterization of new copy mutants of plasmid R1, and identification of a polypeptide involved in copy number control.
    Mol Gen Genet. 1981;181(1):123-30 PMID: 6261082
  12. Nucleotide sequence of the region of the origin of replication of the broad host range plasmid RK2.
    Mol Gen Genet. 1981;181(1):8-12 PMID: 6261086
  13. Molecular genetics of broad host range plasmid RK2.
    Plasmid. 1981 Jan;5(1):10-9 PMID: 6164066
  14. Complementation analysis in Pseudomonas aeruginosa of the transfer genes of the wide host range R plasmid R18.
    Plasmid. 1981 Mar;5(2):202-12 PMID: 6264523
  15. Complementation analysis of replication and maintenance functions of broad host range plasmids RK2 and RP1.
    Plasmid. 1981 May;5(3):277-91 PMID: 7022504
  16. Plasmid RP4 specifies a deoxyribonucleic acid primase involved in its conjugal transfer and maintenance.
    J Bacteriol. 1981 Dec;148(3):769-81 PMID: 6273381
  17. RNAs involved in copy-number control and incompatibility of plasmid R1.
    Proc Natl Acad Sci U S A. 1981 Oct;78(10):6008-12 PMID: 6171808
  18. Broad host range plasmid RK2 encodes multiple kil genes potentially lethal to Escherichia coli host cells.
    Proc Natl Acad Sci U S A. 1982 Mar;79(6):1935-9 PMID: 7043468
  19. Maintenance of broad host range plasmid RK2 replicons in Pseudomonas aeruginosa.
    Nature. 1982 Aug 12;298(5875):674-6 PMID: 6285208
  20. Multiple mechanisms for expression of incompatibility by broad-host-range plasmid RK2.
    J Bacteriol. 1982 Dec;152(3):1078-90 PMID: 6754696
  21. Replication control mutations of plasmid R6-5 and their effects on interactions of the RNA-I control element with its target.
    J Bacteriol. 1983 Apr;154(1):429-36 PMID: 6187730
  22. Host range of conjugation and replication functions of the Escherichia coli sex plasmid Flac. Comparison with the broad host-range plasmid RK2.
    J Mol Biol. 1982 Dec 15;162(3):699-703 PMID: 6820070
  23. 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):3595-8 PMID: 6304722
  24. Deletion mapping of kil and kor functions in the trfA and trfB regions of broad host range plasmid RK2.
    Mol Gen Genet. 1983;190(2):245-54 PMID: 6308390
  25. Conditional lethal mutants of the kilB determinant of broad host range plasmid RK2.
    Plasmid. 1983 Jul;10(1):82-95 PMID: 6353454
  26. Essential genes of plasmid RK2 in Escherichia coli: trfB region controls a kil gene near trfA.
    J Bacteriol. 1983 Nov;156(2):584-91 PMID: 6313609
  27. Instability of a high-copy-number mutant of a miniplasmid derived from broad host range IncP plasmid RK2.
    Plasmid. 1983 Sep;10(2):184-95 PMID: 6356189
  28. Map location and nucleotide sequence of korA, a key regulatory gene of promiscuous plasmid RK2.
    Nucleic Acids Res. 1983 Nov 11;11(21):7453-69 PMID: 6316262
  29. Molecular cloning and mapping of SphI restriction fragments of plasmid RP4.
    Plasmid. 1983 Nov;10(3):303-7 PMID: 6318250
  30. Analysis of copy number control elements in the region of the vegetative replication origin of the broad host range plasmid RK2.
    EMBO J. 1984 Jan;3(1):57-63 PMID: 6323170
  31. The trfA and trfB promoter regions of broad host range plasmid RK2 share common potential regulatory sequences.
    Nucleic Acids Res. 1984 Apr 25;12(8):3619-30 PMID: 6328430
  32. A system to study promoter and terminator signals recognized by Escherichia coli RNA polymerase.
    Gene Amplif Anal. 1981;2:383-415 PMID: 6101056
  33. Post-transcriptional control of expression of the repA gene of plasmid R1 mediated by a small RNA molecule.
    EMBO J. 1983;2(1):93-8 PMID: 11894917
  34. Map of plasmid RP4 derived by insertion of transposon C.
    J Mol Biol. 1977 Jul 5;113(3):455-74 PMID: 328901
  35. Unidirectional replication of the P-group plasmid RK2.
    Biochim Biophys Acta. 1977 Sep 6;478(1):109-13 PMID: 329885
  36. Construction of plasmid R6K derivatives in vitro: characterization of the R6K replication region.
    Plasmid. 1978 Sep;1(4):571-80 PMID: 372982
Article Info
Journal
The EMBO journal
Abbr.
EMBO J
ISSN
0261-4189
Published
1984-07-00
Pages
1513-9
Language
English
Region
England
NLM ID
8208664
PMCID
PMC557552
Subset
IM
External Links
PubMed source PMC Full Text View journal details
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