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Eukaryotic DNA Polymerases

  1. Sue Cotterill1,
  2. Stephen Kearsey2

Published Online: 15 DEC 2009

DOI: 10.1002/9780470015902.a0001045.pub2

eLS

eLS

How to Cite

Cotterill, S. and Kearsey, S. 2009. Eukaryotic DNA Polymerases. eLS. .

Author Information

  1. 1

    St George's Hospital Medical School, London, UK

  2. 2

    University of Oxford, Department of Zoology, Oxford, UK

Publication History

  1. Published Online: 15 DEC 2009

This is not the most recent version of the article. View current version (15 AUG 2014)

Abstract

Deoxyribonucleic acid (DNA) is replicated and repaired by a family of enzymes called DNA polymerases. Eukaryotic cells have a diversity of these enzymes that, while sharing a common biochemical activity, are specialized for particular roles. Three polymerases are required for the replication of the nuclear genome, with pol α involved in priming and initial synthesis and pols δ and ɛ involved in bulk DNA replication. These polymerases are dependent on a large number of other proteins which unwind the DNA and perform other functions essential for efficient DNA synthesis. Polymerases are also involved in DNA repair and many repair-specific enzymes have been identified. Some repair polymerases can refill a gap generated by removal of damaged DNA, or copy a damaged template, allowing DNA synthesis to proceed across a damaged template. Repair polymerases can also have tissue-specific functions in lymphoid cells, where they contribute to somatic hypermutation of immunoglobulin genes.

Key concepts:

  • Catalytic function of DNA polymerases.

  • Concepts of ‘proofreading’ and ‘processivity’.

  • Roles of replicative DNA polymerases needed for chromosome replication and organization at the replication fork.

  • Function of accessory proteins needed for polymerase function in chromosome replication.

  • Different modes of action of specialized polymerases involved in DNA repair.

  • Catalytic mechanism of polymerases.

  • Assays used to detect polymerase function in vitro.

Keywords:

  • replication;
  • DNA repair;
  • DNA synthesis;
  • cell cycle