Binding specificity of T4 DNA polymerase to RNA.

Abstract:

Bacteriophage T4 DNA polymerase, product of phage gene 43 (gp43), is a multifunctional DNA-binding protein and a key component of the phage DNA replicase. It is also an RNA-binding protein that selectively recognizes a site on its mRNA (the translational operator) and represses its own translation. We examined the ability of the protein to discriminate between DNA and RNA by using a gel mobility shift assay with defined RNA and DNA substrates. A higher affinity to RNA as compared with DNA (about 100-fold) was observed in assays that utilized synthetic DNA and in vitro transcribed RNA substrates bearing the T4 gene 43 translational operator sequence. The replacement of thymine with uracil in the synthetic DNA did not improve binding. The results suggest that the protein's selectivity for RNA is based in structure (intramolecular interactions) specific to the ribonucleotide sequence of the operator. Competition studies suggest that the protein determinants for RNA and DNA recognition are only partially overlapping.

Polymerases:

T4

Topics:

Structure and Structure/Function

One line summary:

RNA affinity by T4 DNA polymerase is largely based on the presence of the T4 gp43 translational operator sequence rather than available polymerase substrates

Status:

new topics/pols set partial results complete validated

Results:

No results available for this paper.

Entry validated by:

Log in to edit reference All References

Using Polbase tables:

Sorting:

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).

Filtering:

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.