DNA polymerase

From Proteopedia
Revision as of 18:10, 31 December 2015 by Michal Harel (talk | contribs)
Jump to navigation Jump to search

Template:STRUCTURE 1taq

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.[1] 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.

Prokaryotic DNA polymerases:

  • DNA polymerase I: involved in excision repair. Major polymerase in E. coli.
  • DNA polymerase II: active in replication forks.
  • DNA polymerase III: involved in DNA replication.
  • DNA polymerase IV: involved in non-targeted mutagenesis.
  • DNA polymerase V: involved in translesion synthesis.

Eukaryotic DNA polymerases:

  • Pol α,β,γ,δ,ε,ζ,η,ι,κ
  • 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 polymerase3D Structures of DNA polymerase

Updated on 31-December-2015

ReferencesReferences

  1. Steitz TA. DNA polymerases: structural diversity and common mechanisms. J Biol Chem. 1999 Jun 18;274(25):17395-8. PMID:10364165

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Alexander Berchansky, David Canner, Michal Harel, Joel L. Sussman, Cori Damron, Emily Bray, Jaime Prilusky