RNA priming of DNA replication by bacteriophage T4 proteins.


Bacteriophage T4 DNA replication proteins have been shown previously to require ribonucleoside triphosphates to initiator new DNA chains on unprimed single-stranded DNA templates in vitro. This DNA synthesis requires a protein controlled by T4 gene 61, as well as the T4 gene 41, 43 (DNA polymerase), 44, 45, and 62 proteins, and is stimulated by the gene 32 (helix-destabilizing) protein. In this paper, the nature of the RNA primers involved in DNA synthesis by the T4 proteins has been determined, using phi X174 and f1 DNA as model templates. The T4 41 and "61" proteins synthesize pentanucleotides with the sequence pppA-C(N)3 where N in positions 3 and 4 can be G, U, C, or A. The same group of sequences is found in the RNA at the 5' terminus of the phi X174 DNA product made by the seven T4 proteins. The DNA product chains begin at multiple discrete positions on the phi X174 DNA template. The characteristics of the T4 41 and "61" protein priming reaction are thus appropriate for a reaction required to initiate the synthesis of discontinuous "Okazaki" pieces on the lagging strand during the replication of duplex DNA.




Other Enzymatic Activities, Accessory Proteins/Complexes, Nucleotide Incorporation


new topics/pols set partial results complete validated


Polymerase Reference Property Result Context
T4 Nossal NG1980 Extension from RNA primer Yes

Entry validated by:

Log in to edit reference All References

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.