DNA Polymerase I from E.coli catalyzes the template-directed polymerization of nucleotides into duplex DNA in a 5' to 3´ direction. DNA Polymerase I possesses a 3' to 5´ exonuclease activity or "proof-reading" function, which lowers the error rate during DNA replication, and also contains a 5' to 3´ exonuclease activity, which enables the enzyme to replace nucleotides in the growing strand of DNA by nick translation. The enzyme, purified from recombinant E. coli, is capable of catalyzing de novo synthesis of synthetic homopolymers and provides a convenient method for the preparation of a variety of defined DNA substrates.
Concentration & Storage Condition
Storage Buffer- 50 mM Tris-HCl, pH 7.5, 1 mM DTT, 0.1 mM EDTA, 50% (v/v) glycerol.10x Reaction Buffer- 500 mM Tris-HCl, pH 7.2, 100 mM MgSO₄, 1 mM DTT.Unit Definition- One unit is defined as the amount of enzyme that incorporates 10 nmole of dNTP into TCA-insoluble material in 30 min at 37°C.The reaction conditions are: 67 mM potassium phosphate, pH 7.5, 6.7 mM MgCl₂, 1 mM DTT, 50 μg/ml activated calf thymus DNA and 33 μM dATP, dCTP, dGTP and dTTP (a mix of unlabeled and [³H]dTTP).QC Tests- Activity, exo and endonuclease activity test, SDS-PAGE purity, performance tests.
