title: Four new type I restriction enzymes identified in Escherichia coli clinical isolates.
abstract: Using a plasmid transformation method and the RM search computer program, four type I restriction enzymes with new recognition sites and two isoschizomers (EcoBI and Eco377I) were identified in a collection of clinical Escherichia coli isolates. These new enzymes were designated Eco394I, Eco826I, Eco851I and Eco912I. Their recognition sequences were determined to be GAC(5N)RTAAY, GCA(6N)CTGA, GTCA(6N)TGAY and CAC(5N)TGGC, respectively. A methylation sensitivity assay, using various synthetic oligonucleotides, was used to identify the adenines that prevent cleavage when methylated (underlined). These results suggest that type I enzymes are abundant in E.coli and many other bacteria, as has been inferred from bacterial genome sequencing projects.
authors.affiliation: Division of Microbiology and Molecular Genetics, Department of Biochemistry and Microbiology, Loma Linda University, Loma Linda, CA 92350, USA.
authors.forename: Julie K A
authors.initials: JK
authors.lastname: Kasarjian
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kodama
authors.forename: Masatake
authors.initials: M
authors.lastname: Iida
authors.forename: Katsura
authors.initials: K
authors.lastname: Matsuda
authors.forename: Junichi
authors.initials: J
authors.lastname: Ryu
mesh_terms: D019175:DNA Methylation; D015253:Deoxyribonucleases, Type I Site-Specific / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D010957:Plasmids; D013379:Substrate Specificity; D014170:Transformation, Genetic
chemical_list: D015253:Deoxyribonucleases, Type I Site-Specific