Primer extension rate by DNA polymerase

Value 30 nts/sec
Organism Bacteria Escherichia coli
Reference McDonald WF, Traktman P. Vaccinia virus DNA polymerase. In vitro analysis of parameters affecting processivity. J Biol Chem. 1994 Dec 9 269(49):31190-7. abstract, p.31194 right column bottom paragraph & p.31196 left column 4th paragraphPubMed ID7983061
Method Abstract: "The polymerization and proofreading activities of the vaccinia virus DNA polymerase reside within a 116-kDa catalytic polypeptide. [Investigators] report here an investigation of the intrinsic processivity of this enzyme on both natural and homopolymeric DNA templates. Inclusion of the Escherichia coli helix destabilizing protein allowed the viral enzyme, which lacks strand displacement activity, to utilize a singly primed M13 DNA template."
Comments Abstract: "A primer extension rate of 30 nt/s was observed, and > or = 2000 nt were added per binding event." P.31194 right column bottom paragraph: "Indeed, reducing the MgCl2 concentration from 8 to 1 mM increased the apparent elongation rate during RFII [Replicative Form II] formation from 8 nt/s (RFII in 15 min, Fig. 2, time course) to ≥30 nt/s (RFII in 4 min, Fig. 6B)." P.31196 left column 4th paragraph: "Analysis of extension products from single interactions of the enzyme with the M13 template revealed a >200-fold increase in enzyme processivity when the concentration of MgCl2 was reduced from 8 to 1 mM. A corresponding increase in the apparent rate of primer elongation from 8 nt/s (with excess polymerase) to an average rate of 30 nt/s at 30˚C was also observed."
Entered by Uri M
ID 112758