title: Identification of a methyl-specific restriction system mediated by a conjugative element from Streptomyces bambergiensis.
abstract: pBL2 was identified genetically but not physically in Streptomyces lividans after its mating with S. bambergiensis. During conjugation, pBL2 was transferred at high frequency to S. lividans and S. coelicolor. pBL2.1 DNA isolated from S. coelicolor exconjugants as a circular plasmid was shown to derive from the genome of S. bambergiensis. S. lividans carrying pBL2 or pBL2.1 acquired a methyl-specific restriction (MsrA+) phenotype. The corresponding enzyme was partially purified and shown to resemble a class II endonuclease which cleaves Dam-methylated DNA preferentially.
authors.affiliation: School of Pharmacy, University of Wisconsin, Madison 53706, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Zotchev
authors.forename: H
authors.initials: H
authors.lastname: Schrempf
authors.forename: C R
authors.initials: CR
authors.lastname: Hutchinson
mesh_terms: D003227:Conjugation, Genetic; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics*; D004269:DNA, Bacterial / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics*; D008745:Methylation; D010957:Plasmids / Q000235:genetics*; D015183:Restriction Mapping; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*
chemical_list: D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D015252:Deoxyribonucleases, Type II Site-Specific