Strand annealing and terminal transferase activities of a B-family DNA polymerase.


DNA replication polymerases have the inherent ability to faithfully and rapidly copy a DNA template according to precise Watson-Crick base pairing. The primary B-family DNA replication polymerase (Dpo1) in the hyperthermophilic archaeon, Sulfolobus solfataricus, is shown here to possess a remarkable DNA stabilizing ability for maintaining weak base pairing interactions to facilitate primer extension. This thermal stabilization by Dpo1 allowed for template-directed synthesis at temperatures more than 30 °C above the melting temperature of naked DNA. Surprisingly, Dpo1 also displays a competing terminal deoxynucleotide transferase (TdT) activity unlike any other B-family DNA polymerase. Dpo1 is shown to elongate single-stranded DNA in template-dependent and template-independent manners. Experiments with different homopolymeric templates indicate that initial deoxyribonucleotide incorporation is complementary to the template. Rate-limiting steps that include looping back and annealing to the template allow for a unique template-dependent terminal transferase activity. The multiple activities of this unique B-family DNA polymerase make this enzyme an essential component for DNA replication and DNA repair for the maintenance of the archaeal genome at high temperatures.



Terminal Transferase, Nucleotide Incorporation, Kinetic Parameters, Other, Exonuclease Activity, Source / Purification, Historical Protein Properties (MW, pI, ...)


new topics/pols set partial results complete validated


Polymerase Reference Property Result Context
SsoDpo1 Zuo Z2011 Terminal Transferase Yes
SsoDpo1 Zuo Z2011 Molecular Weight 101kD Technique: SDS-PAGE
SsoDpo1 Zuo Z2011 3-5' Exonuclease (proofreading) Yes
SsoDpo1 Zuo Z2011 Cloned or native Cloned in E. coli
SsoDpo1 Zuo Z2011 Tagged No
SsoDpo1 Zuo Z2011 Full length or truncated Full length
SsoDpo1 Zuo Z2011 Maximum Product Length 10kb
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.