title: Stacking of three different restriction and modification systems in Lactococcus lactis by cotransformation.
abstract: Four plasmids encoding restriction and modification (R/M) systems are described that are different in the specificity of their restrictive activity toward the small isometric phage p2 and prolate phage c2. The R/M plasmids were cotransformed into Lactococcus lactis MG1363 with pVS2, encoding resistance to chloramphenicol and erythromycin, to indicate successful transformation events. Analysis of cotransformants showed that three different R/M plasmids could be combined in L. lactis MG1363. The efficiency at which phage plaqued on the transformants decreased as the number of R/M plasmids increased. Some plasmid combinations were unstable suggesting replicon incompatibility.
authors.affiliation: Department of Food Science, North Carolina State University, Raleigh 27695-7624.
authors.forename: J
authors.initials: J
authors.lastname: Josephsen
authors.forename: T
authors.initials: T
authors.lastname: Klaenhammer
mesh_terms: D002702:Chloramphenicol Resistance / Q000235:genetics; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics* / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology; D013294:Lactococcus lactis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D014169:Transformation, Bacterial
chemical_list: D015280:DNA Restriction-Modification Enzymes; D004917:Erythromycin