DNA polymerase alpha catalytic subunit

DNA polymerase alpha catalytic subunit is an is_associated_with::enzyme that in humans is encoded by the POLA1 is_associated_with::gene.

Function
Pol α has limited is_associated_with::processivity and lacks 3′ is_associated_with::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 is_associated_with::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 is_associated_with::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.

Interactions
DNA dependent polymerase alpha (Pol α) has been shown to interact with is_associated_with::Retinoblastoma protein, is_associated_with::PARP1 and is_associated_with::RBMS1.