Biopolymers and cell. 1985. Volume 1. № 5. 253 - 258

N. V. Belyakova, N. E. Kleiner, T. P. Kravetskaya, O. K. Legina, N. A. Timchenko, V. M. Krutyakov

CORRECTION OF DNA POLYMERASE MISTAKES AND 3'-^5'-EXONUCLEASES OF THE RAT LIVER

Summary

    One of the levels of correcting the DNA polymerase mistakes is the 3'-*-5'-exonuclease «proofreading» activity being absent or non-effective for mammalian DNA polymerases. Cells are supposed to contain correcting 3'->-5'-exonuclease non-bound covalently with DNA polymerases. Three 3'-»-5'-exonucleases are isolated from the rat liver. To study their correcting ability both correct and incorrect [3H] dNMPs are attached to 3'-ends of poly[d(A-T)] by means of DNA polymerase |3 or terminal transferase. The quality of templates obtained is checked by the measurement of correction specificity of the phage T4 DNA polymerase. 3'-*-5'-exonuclease, mainly able of removing non-complementary nucleotides from the DNA primer is established to arise under the liver regeneration.