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Identification of a DNA restriction–modification system in Pectobacterium carotovorum strains isolated from Poland
Author(s) -
Waleron K.,
Waleron M.,
Osipiuk J.,
Podhajska A.J.,
Łojkowska E.
Publication year - 2006
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2005.02766.x
Subject(s) - isoschizomer , pectobacterium carotovorum , restriction enzyme , pectobacterium , biology , endonuclease , microbiology and biotechnology , gene , polymerase chain reaction , dna , genetics , dna methylation , gene expression
Aims: Polish isolates of pectinolytic bacteria from the species Pectobacterium carotovorum were screened for the presence of a DNA restriction–modification (R–M) system. Methods and Results: Eighty‐nine strains of P. carotovorum were isolated from infected potato plants. Sixty‐six strains belonged to P. carotovorum ssp. atrosepticum and 23 to P. carotovorum ssp. carotovorum . The presence of restriction enzyme Pca 17AI, which is an isoschizomer of Eco RII endonuclease, was observed in all isolates of P. c. atrosepticum but not in P. c. carotovorum. The biochemical properties, PCR amplification, and sequences of the Pca 17AI restriction endonuclease and methyltransferase genes were compared with the prototype Eco RII R‐M system genes. Only when DNA isolated from cells of P. c. atrosepticum was used as a template, amplification of a 680 bp homologous to the gene coding EcoRII endonuclease. Conclusions: Endonuclease Pca 17AI, having a relatively low temperature optimum, was identified. PCR amplification revealed that the nucleotide sequence of genes for Eco RII and Pca 17AI R‐M are different. Dcm methylation was observed in all strains of Pectobacterium and other Erwinia species tested. The sequence of a DNA fragment coding Dcm methylase in P. carotovorum was different from that of Escherichia coli . Significance and Impact of the Study: Pca 17AI is the first psychrophilic isoschizomer of Eco RII endonuclease. The presence of specific Dcm methylation in chromosomal DNA isolated from P. carotovorum is described for the first time. A 680 bp PCR product, unique for P. c. atrosepticum strains, could serve as a molecular marker for detection of these bacteria in environmental samples.