Comparison of DIG-11-dUTP utilization by Geobacillus caldoxylosilyticus TK4, Mycobacterium tuberculosis and Escherichia coli DNA polymerases

DNA polymerases are used for many applications and we comparatively investigated DNA synthesis activity of DNA polymerase I enzymes of Geobacillus caldoxylosilyticus TK4, Escherichia coli and Mycobacterium tuberculosis with DIG-11-dUTP using synthetic DNA substrates. We showed that Gca polymerase I and Klenow Fragment (KF) used DIG-11-dUTP instead of dTTP almost at the same ratio, but more efficiently than Mtb polymerase I. We considered that Gca polymerase I could be efficiently used to label a DNA oligonucleotide either internally or at the 3'-terminus by DIG-11-dUTP for the generation of non-radioactive labeled DNA substrates at higher temperature than KF. All three polymerases could not elongate the primer terminus after adding ddNTPs into DNA that is characteristic for all known DNA polymerase I enzymes.