DNA polymerase alpha

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DNA-directed DNA polymerase
EC number2.7.7.7
CAS number9012-90-2
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum

DNA polymerase alpha also known as Pol α is an enzyme complex found in eukaryotes that is involved in initiation of DNA replication. The DNA polymerase alpha complex consists of 4 subunits: POLA1, POLA2, PRIM1, and PRIM2.[1]

Pol α has limited processivity and lacks 3′ exonuclease activity for proofreading errors. Thus it is not well suited to efficiently and accurately copy long templates (unlike Pol Delta and Epsilon). Instead it plays a more limited role in replication. Pol α is responsible for the initiation of DNA replication at origins of replication (on both the leading and lagging strands) and during synthesis of Okazaki fragments on the lagging strand. The Pol α complex (pol α-DNA primase complex) consists of four subunits: the catalytic subunit POLA1, the regulatory subunit POLA2, and the small and the large primase subunits PRIM1 and PRIM2 respectively. Once primase has created the RNA primer, Pol α starts replication elongating the primer with ~20 nucleotides.[1]


DNA polymerase alpha, like DNA primase, contains iron-sulfur clusters, that are critical in electron transport that uses DNA itself to send electrons, and therefore data, at very high speeds, a common example, to detect DNA damage.[2]


  1. ^ a b Lehman IR, Kaguni LS (March 1989). "DNA polymerase alpha" (PDF). J. Biol. Chem. 264 (8): 4265–8. PMID 2647732.
  2. ^ "Electrons use DNA like a wire for signaling DNA replication".

External links[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.