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DNA polymerase

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Revision as of 11:17, 20 October 2015 by Michal Harel (Talk | contribs)
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DNA polymerase (Dpo) reads a DNA strand and catalyzes the synthesis of its complementary strand. Dpo's are divided into 7 families according to their sequence homology and 3D structure similarities. The families are:

  • Family A - replicative or repair Dpo.
  • Family B - replicative Dpo involved in processing DNA replication during cell division (includes eukaryotic Dpo α,δ,ε).
  • Family C - major replicative Dpo in bacteria (includes Dpo II, III, IV).
  • Family D - replicative. Present in archaea.
  • Family X - eukaryotic repair Dpo (includes Dpo β,λ,σ,μ and terminal deoxynucleotidyl transferase).
  • Family Y - replicative of damaged DNA (includes eukaryotic η,ι,κ).
  • Family RT - reverse transcriptase. See Reverse transcriptase.

Some Dpo terminology:
Dpo sliding clamp is made of the complex of Dpo and Proliferating Cell Nuclear Antigen (PCNA) which encircles it.
The BRCT domain in Dpo is the C-terminal domain of breast cancer susceptibility protein.
Klenow fragment is a large Dpo fragment produced upon cleavage of Dpo by subtilisin.
In the E. coli, the EcDpo III subunits β, γ, δ, δ' are named clamp loader. This complex assembles the β subunit sliding clamp unto the DNA.
Rev1 is a Dpo involved in replication over DNA lesions.
Terminal deoxynucleotidyl transferase (TdT) is a family X Dpo expressed in immature lymphoid cells. TdT adds nucleotides to exons during antibody gene recombination.
For more details see

3D Structures of DNA polymerase

Updated on 20-October-2015

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