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A host factor absent from Lactococcus lactis subspecies lactis MG1363 is required for conjugative transposition
Author(s) -
Bringel F.,
Alstine G. L.,
Scott J. R.
Publication year - 1991
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1991.tb01858.x
Subject(s) - biology , lactococcus lactis , transposable element , genetics , enterococcus faecalis , bacillus subtilis , transposition (logic) , plasmid , microbiology and biotechnology , mutant , dna , gene , escherichia coli , bacteria , lactic acid , linguistics , philosophy
Summary In matings between Lactococcus lactis strains, the conjugative transposons Tn916 and Tn919are found in the chromosome of the transconjugants in the same place as in the chromosome of the donor, indicating that no transposition has occurred. In agreement with this, the frequency of L. lactis transconjugants from intraspecies matings is the same whether the donor contains the wild‐type form of the transposon or the mutant Tn916‐int1 , which has an insertion in the transposon's integrase gene. However, in intergeneric crosses with Bacillus subtilis or Enterococcus faecalis donors, Tn916 and Tn919 transpose to different locations on the chromosome of the L. lactis transconjugants. Moreover, Tn916 and Tn919 could not be transferred by conjugation from L. lactis and B. subtilis, E. faecalis or Streptococcus pyogenes. This suggests that excision of these elements does not occur in L. lactis. When cloned into E. coli with adjacent chromosomal DNA from L. lactis , the conjugative transposons were able to excise, transpose and promote conjugation. Therefore, the inability of these elements to excise in L. lactis is not caused by a permanent structural alteration in the transposon. We conclude that L. lactis lacks a factor required for excision of conjugative transposons.