UniProt functional annotation for P28632

UniProt code: P28632.

Organism: Escherichia coli (strain K12).
Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.
 
Function: Part of the beta sliding clamp loading complex, which hydrolyzes ATP to load the beta clamp onto primed DNA to form the DNA replication pre-initiation complex (PubMed:2040637). DNA polymerase III is a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria. This DNA polymerase also exhibits 3' to 5' exonuclease activity. The exact function of the psi subunit is unknown. {ECO:0000269|PubMed:2040637}.
 
Catalytic activity: Reaction=a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1); Xref=Rhea:RHEA:22508, Rhea:RHEA-COMP:11130, Rhea:RHEA-COMP:11131, ChEBI:CHEBI:33019, ChEBI:CHEBI:61560, ChEBI:CHEBI:83828; EC=2.7.7.7;
Subunit: The DNA polymerase III holoenzyme complex contains at least 10 different subunits organized into 3 functionally essential subassemblies: the Pol III core, the beta sliding clamp processivity factor and the clamp-loading complex. The Pol III core (subunits alpha, epsilon and theta) contains the polymerase and the 3'-5' exonuclease proofreading activities (PubMed:2040637). The polymerase is tethered to the template via the dimeric beta sliding clamp processivity factor. The clamp-loading complex (also called gamma complex) assembles the beta sliding clamp onto the primed template and plays a central role in the organization and communication at the replication fork. The clamp- loading complex contains delta, delta', psi and chi, and 3 copies of either or both of two different DnaX proteins, gamma and tau. The DNA replisome complex has a single clamp loader (3 tau and 1 each of delta, delta', psi and chi subunits) which binds 3 Pol III cores (1 core on the leading strand and 2 on the lagging strand) each with a beta sliding clamp dimer. Additional proteins in the replisome are other copies of gamma, psi and chi, Ssb, DNA helicase and RNA primase (PubMed:20413500, PubMed:22157955). The clamp loader hydrolyzes ATP to assemble the beta processivity factor onto the primed template (PubMed:2040637) and plays a central role in the organization and communication at the replication fork. {ECO:0000269|PubMed:2040637, ECO:0000269|PubMed:20413500, ECO:0000269|PubMed:22157955}.

Annotations taken from UniProtKB at the EBI.