BIO370Y5 Study Guide - Midterm Guide: Hydroxylamine, Pyrimidine, Streptomycin
Document Summary
Dna -1950s luria, bertani and weigle found evidence of primitive immune sys. E. coli restricting growth of replication of phages) -1962 arber found evidence that resistance is from enzyme which mods host dna and kills foreign dna (basically, host dna is methylated and foreign dna is cleaved) -types of endonucs. T1 and t3: both have restriction and mod activity, do not cut w/i seq. nd use atp to move near cleavage type. Site t3: cuts near recog site t2: only has restriction activity, mods happen only if a counterpart enzyme exists that recogs same seq. only uses mg2+ (not atp). Cut w/i or beside recog site and most useful in microbio, since it is predictable. Site b/c more effective since you can cut at either end. Nics are made in phosphodiester bonds -4^n = size of possible fragment -1/4^n = odds of cut occurring -1/4^n x size of plasmid = number of fragments on gel.
