RESTRICTION ENZYMESRESTRICTION ENZYMESCell and Molecular Biology LabCell and Molecular Biology Lab Department of Biological Sciences Department of Biological SciencesUST College of Science UST College of SciencePost Lab Discussion # 5 Post Lab Discussion # 5Restriction EnzymesRestriction EndonucleasesCleave DNA at specifc sequencesResponsible for host-controlled restriction modifcation or phenotype modifcation (in bacteria!ro"th of pha!es are #restricted$ to certain strains (%uria& '()*#Restriction$ + bacterial ,immunity- a!ainst non-self& unmethylated DNACornerstone of molecular biolo!y'(./ Nobel 0rize in 1edicine to 2erner Arber& Daniel Nathans& 3amilton 4mithBACT!"AL !ST!"CT"#$ $%&MS2ith t"o components5Restriction endonuclease - sequence specifc nucleasesDNA methylase + modifes DNA by methylation (prevents cleava!e of o"n DNA6 (** 7no"n REs8solated from 9:* species of bacteriaRE 0R;0ERourth letter + frst?second letter of strain name of or!anism "here RE "as isolatedRoman numeral + number (accordin! to order of discovery of RE isolated from the species@EAamples5EcoR 8 + Escherichia coli (RB': strain3ind 888 + Haemophilus infuenzae (Rd strain4ma 8 + Serratia marcescens