A helicase–primase complex (also helicase-primase, Hel/Prim, H-P or H/P) is a complex of enzymes including DNA helicase and DNA primase.
A helicase-primase associated factor protein may also be present.
[1] The complex is used by herpesviruses, in which it is responsible for lytic DNA virus replication.
[2][3][4] In many dsDNA viruses, primase and helicase are fused into a single polypeptide chain, so that the primase and helicase domains correspond to the N-terminal and C-terminal parts of the protein, respectively.
[5] A helicase-primase inhibitor (HPI) is a drug that blocks this action through acting as an enzyme inhibitor.