title: Prevalence of CTGCAG recognizing restriction and modification systems in ruminal selenomonades.
abstract: Analysis of restriction and modification activities in natural population of Selenomonas ruminantium have revealed the prevalence of CTGCAG (Pst I isoschizomers) recognizing restriction and/or modification systems in these bacteria. Pst I isoschizomeric restriction endonucleases were detected in 4 out of 15 strains tested. In one strain, the Pst I isoschizomeric restriction system was accompanied by another restriction and modification system recognizing GAATTC sequence (Eco RI isoschizomer). Four other strains contained CTGCAG specific methylases which lacked cognate endo-nuclease activities. Presence of identical restriction and modification systems in both of subspecies of S. ruminantium, as well as the occurrence of Pst I isoschizomers in various combinations, indicate the possibility of horizontal transfer of genes coding for these systems.
authors.affiliation: Institute of Animal Physiology, Slovak Academy of Sciences, Soltesovej 4-6, 04001, Kosice, Slovak Republic.
authors.forename: V
authors.initials: V
authors.lastname: Molnarova
authors.forename: P
authors.initials: P
authors.lastname: Pristas
authors.forename: P
authors.initials: P
authors.lastname: Javorsky