Poliovirus RNA-dependent RNA polymerase (3Dpol) is sufficient for template switching in vitro.


We have performed a systematic, quantitative analysis of the kinetics ...
We have performed a systematic, quantitative analysis of the kinetics of nucleotide incorporation catalyzed by poliovirus RNA-dependent RNA polymerase, 3Dpol. Homopolymeric primer/templates of defined length were used to evaluate the contribution of primer and template length and sequence to the efficiency of nucleotide incorporation without the complication of RNA structure. Interestingly, thermodynamic stability of the duplex region of these primer/templates was more important for efficient nucleotide incorporation than either primer or template length. Surprisingly, products greater than unit length formed in all reactions regardless of length or sequence. Neither a distributive nor a processive slippage mechanism could be used to explain completely the formation of long products. Rather, the data were consistent with a template-switching mechanism. All of the nucleotide could be polymerized during the course of the reaction. However, very few primers could be extended, suggesting an inverse correlation between the efficiency of primer utilization and that of nucleotide incorporation. Therefore, the greatest fraction of incorporated nucleotide derives from a small fraction of enzyme when radioactive nucleotide and homopolymeric primer/template substrates are employed. The impact of these results on mechanistic studies of 3Dpol-catalyzed nucleotide incorporation and RNA recombination are discussed.




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.