title: Cloning of the YenI restriction endonuclease and methyltransferase from Yersinia enterocolitica serotype O8 and construction of a transformable R-M+ mutant.
abstract: Two different clonal groups of pathogenic Yersinia enterocolitica strains, American and non-American, have been recognized. These are distinguished by a number of criteria, including their virulence in a murine model of infection. However, genetic analysis of virulence in American strains has been hampered due to the severe restriction of transformed or electroporated DNA. Thus, we cloned the yenIMR locus from the American serotype strain 8081c, which encodes YenI, an isoschizomer of PstI. This clone encodes both the restriction endonuclease and methyltransferase. The location of the genes on the clone was determined and this information was used to construct a small deletion (400 bp) that results in an R-M+ phenotype. This mutation was recombined onto the Y. enterocolitica chromosome to give an R-M+ mutant which showed at least a 1000-fold increase in electroporation frequency compared to the wild-type strain. Southern analysis using a probe derived from yenIMR indicated that American serotype strains have this locus whereas non-American serotype strains do not.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of California, Los Angeles 90024.
authors.forename: S A
authors.initials: SA
authors.lastname: Kinder
authors.forename: J L
authors.initials: JL
authors.lastname: Badger
authors.forename: G O
authors.initials: GO
authors.lastname: Bryant
authors.forename: J C
authors.initials: JC
authors.lastname: Pepe
authors.forename: V L
authors.initials: VL
authors.lastname: Miller
mesh_terms: D002874:Chromosome Mapping; D003001:Cloning, Molecular; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics*; D014170:Transformation, Genetic; D014774:Virulence / Q000235:genetics; D015008:Yersinia enterocolitica / Q000201:enzymology* / Q000472:pathogenicity
chemical_list: C059681:DNA modification methylase PstI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C024388:CTGCAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific