Why DNA Polymerase III Holoenzyme can synthesize DNA with very high fidelity?

As you well know, DNA Polymerase III Holoenzyme (Pol III HE) is the major polymerase involved in DNA replication. During DNA replication, new strand is synthesized by adding nucleotides to the 3′ terminus of the primer that are complementary to the original DNA template strand. DNA synthesis by Pol III HE is very high fidelity with the error rate is low as 10–6 to 10–8. So, which factor contributes to this accuracy of Pol III HE? Pol III HE is a big molecule that consists of 10 different subunits. Continue Reading →

DNA Polymerase III Holoenzyme

Pol III Holoenzyme is a big molecule that consists of 10 different subunits. Three subunits alpha, epsilon and theta form the core and there are 2 cores in a Pol III Holo enzyme complex that linked by tau subunit. Each core is responsible for leading and lagging synthesis. The gamma complex (clamp loader) is composed of gamma, delta, delta prime, chi and psi subunits; take in charge in loading beta clamp onto primed DNA. The complex consist of two cores and the gamma complex is called as Polymerase III*. When beta clamp is added to each Continue Reading →