What is the role of the DNA polymerase III?

DNA Polymerase III, Bacterial DNA polymerase III holoenzyme (Pol III HE) is an enzyme that catalyzes elongation of DNA chains during bacterial chromosomal DNA replication. Together with a DNA helicase and a primase, Pol III HE participates in the replicative apparatus that acts at the replication fork.

When DNA polymerase 3 is been activated?

Being the primary holoenzyme involved in replication activity, the DNA Pol III holoenzyme also has proofreading capabilities that corrects replication mistakes by means of exonuclease activity reading 3’→5′ and synthesizing 5’→3′. DNA Pol III is a component of the replisome, which is located at the replication fork.

Is DNA polymerase 3 a dimer?

Physical studies as well as genetic studies argue that the DNA polymerase III holoenzyme complex exists in a dimer form. The holoenzyme comprises two dimerized β subunits (β4), a dimeric core Pol III (α2ε2θ2) and a single γ complex (γ1τ2δ1δ′1χ1ψ1) that loads the β processivity clamp onto the DNA template.

What is the function of DNA polymerase III?

Find Dna Polymerase Iii Function. The enzyme DNA polymerase III is the primary enzyme involved with bacterial DNA replication. It performs the 5′-3′ polymerase function, which means that it adds nucleotides to the 3′ end of the forming DNA strand during replication. Before replication can start, the enzyme helicase unwinds the two DNA strands.

Is the dimer of DNA polymerase 3 symmetrical?

The stoichiometry of the various subunits suggests that the dimer is not exactly symmetrical, but it does appear to be symmetrical for the α, β, and ε subunits.

What is the clamp loader of DNA polymerase III?

The clamp loader uses the energy of ATP to open up the clamp and load it around double-stranded DNA at template–primer junctions. The clamp loader for the β subunit sliding clamp is a complex consisting of the γ, τ, δ, δ ′, ξ, and χ subunits of DNA polymerase III holoenzyme (8–10).

How does DNA polymerase III holoenzyme fill in the gap?

One of the four exonucleases (ExoI, ExoVII, ExoX, and RecJ) excises the DNA fragment from the nick generated by MutH to just past the mismatch. DNA polymerase III holoenzyme (a multiprotein complex) then fills-in the single-stranded gap and the nick is sealed by DNA ligase.