Influence of divalent metal activator on the specificity of misincorporation during DNA synthesis catalyzed by DNA polymerase I of Escherichia coli.

Lai MD, Beattie KL
Mutation research (1988), Volume 198, Page 27
PubMed entry


To test whether the identity of divalent metal activator affects the ...
To test whether the identity of divalent metal activator affects the specificity of misincorporation during polymerization catalyzed by E. coli DNA polymerase I, we carried out the following procedure. A series of oligonucleotide primers, annealed at different positions along the lacZ region of bacteriophage M13mp9 DNA, were elongated in the presence of 3 of the 4 deoxynucleoside 5'-triphosphates (dNTPs) until one or a few misincorporations occurred in each elongated primer. The elongated primers (containing deoxynucleotide residues that had been misincorporated in the presence of either Mg2+ or Mn2+) were then isolated and sequenced by the 'dideoxy' chain termination method to determine the identity of deoxynucleoside monophosphates (dNMPs) that had been misincorporated at different template positions during the original 'minus' reactions, activated by Mg2+ or Mn2+. The results obtained by this approach revealed that both the type of misincorporation and the effect of substituting Mn2+ for Mg2+ depended on the nucleotide sequence of the template. At 40% of the template positions at which misincorporation was compared with both metal ions (8 out of 20), the identity of mispairs differed significantly for synthesis activated by Mn2+ versus Mg2+. Of these 8 sites, 4 exhibited increased transversions in the presence of Mn2+, while 4 exhibited decreased transversions with Mn2+.




new topics/pols set partial results complete validated


No results available for this paper.

Entry validated by:

Using Polbase tables:


Tables may be sorted by clicking on any of the column titles. A second click reverses the sort order. <Ctrl> + click on the column titles to sort by more than one column (e.g. family then name).


It is also possible to filter the table by typing into the search box above the table. This will instantly hide lines from the table that do not contain your search text.