DNA polymerase III proofreading complex

Species: Escherichia coli (strain K12); 83333
Accession number: EBI-6467979

Summary


Systematic Name:

2xholE:2xdpo3A:2xdpo3E

Synonyms:
polymerase subcomplex of the DNA polymerase III complex DNA polymerase III proofreading complex
DNA polymerase III proof-reading complex DNA polymerase III proofreading subcomplex
DNA polymerase III proof-reading subcomplex DNA polymerase III core complex
Pol III Pol III complex
Pol III subcomplex polymerase subcomplex of the DNA polymerase III complex
DNA polymerase III proof-reading complex DNA polymerase III proofreading subcomplex;
DNA polymerase III proof-reading subcomplex; DNA polymerase III core complex;
Pol III subcomplex Pol III complex
Pol III
Bioactive entity
Protein
- click or tap to toggle between circle and bar (bar shows binding sites, if known)
Gene
DNA
RNA


Function:

Functions as the leading- and lagging-strand replicase in DNA replication. Pol III alone exhibits a very low processivity, additional interactions stabilize the interaction of Pol III with the replication fork and increase its processivity. The polymerase subunit of the DNA polymerase III holoenzyme (EBI-6467913) contains three participants: the polymerase subunit alpha and the two proofreading subunits, epsilon and theta. While two polymerase subcomplexes elongate the leading and lagging strands the function of the third polymerase subcomplex - bound to the third tau subunit of the clamp loading complex (EBI-6467993) - is as of yet unknown. The beta and tau subunits of the Pol III holoenzyme appear to be competing for the same binding site on alpha. This competition allows for the clamp loader (EBI-6467993) to disengage from the polymerase unit and facilitate binding of alpha to the sliding clamp (EBI-6468862) to commence strand elongation. At the end of replication the tau subunit re-connects with alpha displacing the polymerase subcomplex from the newly-synthesised double-stranded DNA.

Properties:

The C-terminal domain of the alpha subunits of two polymerase trimers each interact with a sliding clamp beta subcomplex (EBI-6468862) and a tau subunit of the clamp-loading complex (EBI-6467993). A third polymerase subcomplex is bound to the third tau subunit but not to the third beta subcomplex.


Participants

ID Name Description Stoichiometry Biological Role Interactor Type Other Features
P10443
dnaE DNA polymerase III subunit alpha 2 enzyme protein
binding region P10443 [1-1160]
required to bind P10443 [1112-1160]
P03007
dnaQ DNA polymerase III subunit epsilon 2 enzyme protein
P0ABS8
holE DNA polymerase III subunit theta 2 unspecified role protein

Cross References

Type Database Identifier Description
cellular component gene ontology GO:0044776 DNA polymerase III, core complex
Experimental evidence that interaction occurs intact EBI-6392934
evidence ontology ECO:0000353
Experimental evidence that interaction occurs intact EBI-6858549
additional information pubmed 14630952
additional information pubmed 20413500
cellular component gene ontology GO:0005829 cytosol
biological process gene ontology GO:0006273 lagging strand elongation
molecular function gene ontology GO:0003887 DNA-directed DNA polymerase activity
molecular function gene ontology GO:0003677 DNA binding
biological process gene ontology GO:0006272 leading strand elongation
additional information pubmed 21675919
identical object in an external resource intenz 2.7.7.7
Curated by: IntAct