1976/09/01 by A J Chien, D. Edgar, John M. Trela · 3 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · #DNA and Nucleic Acid Chemistry #Advanced biosensing and bioanalysis techniques #Chemical Reaction Mechanisms
paper · pdf · doi:10.1128/jb.127.3.1550-1557.1976
openalex publication_date 1976/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
A stable deoxyribonucleic acid (DNA) polymerase (EC 2.7.7.7) with a temperature optimum of 80 degrees C has been purified from the extreme thermophile Thermus aquaticus. The enzyme is free from phosphomonoesterase, phosphodiesterase and single-stranded exonuclease activities. Maximal activity of the enzyme requires all four deoxyribonucleotides and activated calf thymus DNA. An absolute requirement for divalent cation cofactor was satisfied by Mg2+ or to a lesser extent by Mn2+. Monovalent cations at concentrations as high as 0.1 M did not show a significant inhibitory effect. The pH optimum was 8.0 in tris(hydroxymethyl)aminomethane-hydrochloride buffer. The molecular weight of the enzyme was estimated by sucrose gradient centrifugation and gel filtrations on Sephadex G-100 to be approximately 63,000 to 68,000. The elevated temperature requirement, small size, and lack of nuclease activity distinguish this polymerase from the DNA polymerase of Escherichia coli.