Elsevier

Plasmid

Volume 44, Issue 2, September 2000, Pages 163-172
Plasmid

Regular Article
Characterization of the IncW Cryptic Plasmid pXV2 from Xanthomonas campestris pv. vesicatoria

Communicated by Donald Helsinki
https://doi.org/10.1006/plas.2000.1468Get rights and content

Abstract

The gram-negative plant pathogen Xanthomonas campestris pv. vesicatoria strain Xv2 harbors an indigenous, cryptic plasmid pXV2 of 14.6 kb. This plasmid can only be maintained in Xanthomonas and is incapable of self-transmission. However, incompatibility testing classified it in IncW, a group containing the smallest number of naturally occurring, broad-host-range, conjugative plasmids. A pXV2 derivative containing only a 5.5-kb PstI fragment is stably maintained. Deletion of a 3.0-kb region from the PstI fragment causes a loss of plasmid stability. Nucleotide sequencing of the 2.1-kb region essential for autonomous replication revealed a repA gene and a downstream noncoding region containing four iterons, two 17- and two 19-nt direct repeats, and an AT-rich region lying between the two sets of iterons. The sequence of the deduced RepA and the iterons shows homology to the RepA (39% identity) and the iterons, respectively, of the IncW plasmid pSa. Maxicell expression of the repA gene produced a protein of 35 kDa, a size similar to that deduced from the nucleotide sequence. Trans-complementation test confirmed that the repA gene and the iterons are indeed the essential elements for pXV2 replication.

References (40)

  • D.A. Cooksey et al.

    Copper resistance gene homologs in pathogenic and saporphytic bacterial species from tomato

    Appl. Environ. Microbiol.

    (1990)
  • G. del Solar et al.

    Replication and control of circular bacterial plasmids

    Microbiol. Mol. Biol. Rev.

    (1998)
  • V. Dittapongpitch et al.

    Small, conjugatable plasmid in copper-resistant strains of Xanthomonas campestris pv. vesicatoria

    Phytopathology

    (1989)
  • V. Dittapongpitch et al.

    Indigenous miniplasmids in strains of Xanthomonas campestris pv. vesicatoria

    Phytopathology

    (1993)
  • R. Grosschedl et al.

    DNA sequences and structural homologies of the replication origins of lambdoid bacteriophages

    Nature

    (1979)
  • B. Kearney et al.

    Characterization of IS476 and its role in bacterial spot disease of tomato and pepper

    J. Bacteriol.

    (1990)
  • U.K. Laemmli

    Cleavage of structural proteins during the assembly of the head of bacteriophage T4

    Nature

    (1970)
  • M. Lai et al.

    Transmission of R plasmids among Xanthomonas spp. and other plant pathogenic bacteria

    Phytopathology

    (1977)
  • G.R. Lazo et al.

    Conservation of plasmid DNA sequences and pathovar identification of strains of Xanthomonas campestris

    Phytopathology

    (1987)
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