Maximum DNA synthesis rate by Polymerase δ

Value 87 sec^-1 Range: ±5.7 Table - link sec^-1
Organism Human Homo sapiens
Reference Meng X, Zhou Y, Lee EY, Lee MY, Frick DN. The p12 subunit of human polymerase delta modulates the rate and fidelity of DNA synthesis. Biochemistry. 2010 May 4 49(17):3545-54. p.3549 table 1PubMed ID20334433
Method P.3546 left column 2nd paragraph: "In this study, [investigators] examined the kinetics of DNA synthesis and degradation catalyzed by Pol δ3 and Pol δ4 and their exonuclease-deficient mutants to provide insights into the nature of their functional differences. The rates of DNA synthesis were examined by pre-steady-state kinetic analysis and reveal that the loss of p12 decreases kpol. Analysis of the rates of exonuclease activity reveals that the rate of translocation of DNA from pol to exo catalytic sites is increased when p12 is absent. Both changes are consistent with the exhibition of an antimutator phenotype for Pol δ3, in which Pol δ4 is less likely to proofread and more likely to extend mismatched primers. Thus, loss of p12 modulates both the rate and fidelity of DNA synthesis by facilitating a more rapid and frequent transfer of the DNA primer from the polymerase to the exonuclease active center. These findings provide novel insights into the role of p12 in human Pol δ function at the mechanistic level and into the potential cellular consequences of the in vivo conversion of Pol δ4 to Pol δ3."
Comments P.3549 left column bottom paragraph: "The values of kpol for Pol δ4 and Pol δ3 determined from these experiments were 87 ± 5.7 and 19 ± 2.9 s^−1, respectively. Values of KdNTP for Pol δ4exo− and Pol δ3exo− for the incorporation of dGTP obtained in the same analysis for Pol δ4exo− and Pol δ3exo− were 3.6 ± 0.8 and 3.2 ± 1.6 μM, respectively, showing that binding affinities for dNTP are not affected by p12." See BNID 104136
Entered by Uri M
ID 105486