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Combinational variation of restriction modification specificities in Lactococcus lactis
Author(s) -
Schouler Catherine,
Gautier Michel,
Ehrlich S. Dusko,
Chopin MarieChristine
Publication year - 1998
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 - 10.1046/j.1365-2958.1998.00787.x
Subject(s) - biology , plasmid , lactococcus lactis , genetics , gene , phenotype , protein subunit , dna , auxotrophy , escherichia coli , bacteria , lactic acid
Three genes coding for a type I R‐M system related to the class C enzymes have been identified on the chromosome of Lactococcus lactis strain IL1403. In addition, plasmids were found that encode only the HsdS subunit that directs R‐M specificity. The presence of these plasmids in IL1403 conferred a new R‐M phenotype on the host, indicating that the plasmid‐encoded HsdS is able to interact with the chromosomally encoded HsdR and HsdM subunits. Such combinational variation of type I R‐M systems may facilitate the evolution of their specificity and thus reinforce bacterial resistance against invasive foreign unmethylated DNA.