Restriction Enzyme Ms. Sreylen MEAS Mr. Channratha PRUM Mr. Boonkird Choksukchalalai Mr. Thoranin Intarajakra

contents Salvador Luria and Mary Human Various phages were host specific, with each phage surviving and flourishing only in one host bacterial strain and growing poorly in others Stuart Linn and Werner Aber E.coli was able to protect itself against foreign DNA through some sort of enzymatically catalyzed genetic defense mechanism Hamilton Smith and Kent Wilcox They isolated and characterized the first restriction enzyme from a second bacterial species, Haemophilus influenzae and degrades foreign phage DNA but not the bacterial host's DNA The enzyme has the ability to recognize specific DNA sequences

Daniel Nathans and Kathleen Danna Demonstrated HindII cleaved DNA of the SV40 virus into 11 well defined fragments and how controlled piece these fragments together to construct the complete genetic map of SV40 DNA. endonuclease of Hemophilus influenzae Janet Mertz and Ronald Davis They discovered another restriction enzyme, EcoR1, by contrast, cleaves its recognition site in a staggered way that generates fragments with single-stranded overhanging ends known as cohesive, or sticky, ends

reference -Mertz, J. E., & Davis, R. W. Cleavage of DNA by RI restriction endonuclease generates cohesive ends. Proceedings of the National Academy of Sciences 69, 3370–3374 (1972) -Smith, H. O. and K. W. Wilcox A restriction enzyme from Haemophilus influenzae: I. Purification and general properties. J. Mol. Biol. 51: