title: Effect of Bacillus subtilis  BsuM restriction-modification on plasmid transfer by polyethylene glycol-induced protoplast fusion.
abstract: Polyethylene glycol (PEG)-induced cell fusion is a promising method to transfer larger DNA from one cell to another than conventional genetic DNA transfer systems. The laboratory strain Bacillus subtilis 168 contains a restriction (R) and modification (M) system, BsuM, which recognizes the sequence 5'-CTCGAG-3'. To study whether the BsuM system affects DNA transfer by the PEG-induced cell fusion between R(+)M(+) and R(-)M(-) strains, we examined transfer of plasmids pHV33 and pLS32neo carrying no and eight BsuM sites, respectively. It was shown that although the transfer of pLS32neo but not pHV33 from the R(-)M(-) to R(+)M(+) cells was severely restricted, significant levels of transfer of both plasmids from the R(+)M(+) to R(-)M(-) cells were observed. The latter result shows that the chromosomal DNA in the R(-)M(-) cell used as the recipient partially survived restriction from the donor R(+)M(+) cell, indicating that the BsuM R(-)M(-) strain is useful as a host for accepting DNA from cells carrying a restriction system(s). Two such examples were manifested for plasmid transfer from Bacillus circulans and Bacillus stearothermophilus strains to a BsuM-deficient mutant, B. subtilis RM125.
authors.affiliation: Institute of Oceanic Research and Development, Tokai University, Shimizu, Shizuoka, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Maehara
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Itaya
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ogura
authors.forename: Teruo
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D002459:Cell Fusion; D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial / Q000378:metabolism; D022761:Gene Transfer, Horizontal; D010957:Plasmids; D011092:Polyethylene Glycols / Q000378:metabolism; D011523:Protoplasts; D014169:Transformation, Bacterial
chemical_list: D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial; D011092:Polyethylene Glycols