DNA primase, large subunit, eukaryotic (IPR016558)

Short name: DNA_primase_lsu_euk

Overlapping homologous superfamilies


Family relationships


DNA primase is the polymerase that synthesises small RNA primers for the Okazaki fragments made during discontinuous DNA replication. Primases are grouped into two classes, bacteria/bacteriophage and archaeal/eukaryotic. The proteins in the two classes differ in structure and the replication apparatus components. Archaeal/eukaryotic core primase is a heterodimeric enzyme consisting of a small catalytic subunit (PriS or Pri1) and a large subunit (PriL or Pri2). In the yeast Saccharomyces cerevisiae the small subunit is 48kDa and the large subunit 58kDa [PMID: 2528682]. In eukaryotic organisms, a heterotetrameric enzyme formed by DNA polymerase alpha, the B subunit and two primase subunits has primase activity. Although the catalytic activity and the the ATP binding site reside within PriS [PMID: 2023935], the PriL subunit is essential for primase function as disruption of the PriL gene in yeast is lethal. PriL is composed of two structural domains. Several functions have been proposed for PriL such as stabilization of the PriS, involvement in synthesis initiation, improvement of primase processivity, determination of product size and transfer of the products to DNA polymerase alpha [PMID: 16273105]. Primase function has also been demonstrated for human and mouse primase subunits [PMID: 8026492].

This group represents the eukaryotic DNA primase, large subunit.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0016779 nucleotidyltransferase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.