Four new type I restriction enzymes identified in Escherichia coli clinical isolates.
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.
Kasarjian
Julie K A
JK
Division of Microbiology and Molecular Genetics, Department of Biochemistry and Microbiology, Loma Linda University, Loma Linda, CA 92350, USA.
Kodama
Yoshiaki
Y
Iida
Masatake
M
Matsuda
Katsura
K
Ryu
Junichi
J
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
D015253:Deoxyribonucleases, Type I Site-Specific