A new form of DNA polymerase 3 and a copolymerase replicate a long, single-stranded primer-template.

Abstract:

A new form of DNA polymerase III, termed Pol III star (Pol III(*)), has been purified to homogeneity from Escherichia coli. Pol III(*) is temperature sensitive when isolated from a thermo-sensitive dnaE mutant, as had been described for Pol III. Pol III(*) and Pol III are separable by gel filtration. Pol III(*) utilizes a duplex template containing short gaps with the same catalytic properties as Pol III. However, Pol III(*) is able to replicate long, singlestranded templates such as homopolymer chains and viral circles of M13 and varphiX174 if provided with the following: spermidine, a primer fragment, and a new protein, termed copolymerase III(*) (Copol III(*)). The latter, purified to homogeneity, has no known independent enzymatic activity and supports synthesis by Pol III(*) but not by Pol I, Pol II, or Pol III.

Polymerases:

Topics:

Historical Protein Properties (MW, pI, ...), Other Enzymatic Activities, Modulators/Inhibitors, Accessory Proteins/Complexes, Nucleotide Incorporation

Status:

new topics/pols set partial results complete validated

Results:

Polymerase Reference Property Result Context
Eco Pol III* Wickner W1973 Extension from RNA primer Yes
Eco Pol III* Wickner W1973 Specific Activity 1800 units/mg
Eco Pol III* Wickner W1973 Nucleotide incorporation accessory protein(s) copolymerase III*
Eco Pol III* Wickner W1973 Percent/Fold Effect 99 % decrease Reaction: Nucleotide incorporation; Substrate: dNTPs; Experimental conditions: Spermidine (0mM)
Eco Pol III* Wickner W1973 Gap Filling Yes

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.