DNA topoisomerase I is purified from E.coli strain containing Vaccinia topoisomerase I gene.Vaccinia DNA topoisomerase I is a type I eukaryotic topoisomerase that removes positive and negative supercoiling from covalently closed DNA. The DNA topoismerase I mediates ATP-independent breakage of single-stranded DNA, followed by passage and rejoining. When a topoisomerase transiently breaks a DNA backbone bond, it simultaneously forms a protein-DNA link, in which a tyrosyl oxygen in the enzyme is joined to a DNA phosphorus at one end of the enzyme-severed DNA strand.
Concentration & Storage Condition- 10 unit/㎕. Store at -20℃. 10x Reaction Buffer- 200 mM Tris-acetate, pH7.9, 500 mM K-acetate, 100 mM Mg-acetate, 10 mM DTT Storage Buffer- 50 mM Tris-HCl, pH 7.5, 0.1 M NaCl, 0.1 mM EDTA, 1 mM DTT, 0.1% Triton X-100, 50% glycerol - One unit of DNA topoisomerase I converts 1 ㎍ of supercoiled DNA to relaxed closed circular DNA in 1 hour at 37°C.
- Activity, exo and endonuclease activity test, SDS-PAGE purity, performance tests.