DNA primase and DNA polymerase required to tolerate replication-stalling lesions by bypassing them. Required to facilitate mitochondrial and nuclear replication fork progression by initiating de novo DNA synthesis using dNTPs and acting as an error-prone DNA polymerase able to bypass certain DNA lesions (By similarity). Shows a high capacity to tolerate DNA damage lesions such as 8oxoG and abasic sites in DNA (By similarity). Provides different translesion synthesis alternatives when DNA replication is stalled: able to synthesize DNA primers downstream of lesions, such as UV lesions, R-loops and G-quadruplexes, to allow DNA replication to continue (By similarity). Can also realign primers ahead of 'unreadable lesions' such as abasic sites and 6-4 photoproduct (6-4 pyrimidine-pyrimidinone), thereby skipping the lesion. Also able to incorporate nucleotides opposite DNA lesions such as 8oxoG, like a regular translesion synthesis DNA polymerase. Also required for reinitiating stalled forks after ultraviolet (UV) damage during nuclear DNA replication. Required for mitochondrial DNA (mtDNA) synthesis and replication, by reinitiating synthesis after UV damage or in the presence of chain-terminating nucleotides. In addition to its role in DNA damage response, also required to maintain efficient nuclear and mitochondrial DNA replication in unperturbed cells (By similarity). Can act both with Mn(2+) and Mg(2+) as cofactor in vitro, but Mn(2+) is the preferred cofactor in vivo. The zinc knuckle motif binds zinc and is required for the DNA primase activity. It facilitates the binding and selection of the 5'-nucleotide of the newly synthesized primer and the recognition of preferred initiation sites. The presence of an Asp-Aaa-Glu (DxE) motif in the metal-binding active site favors the use of Mn(2+) ions to achieve optimal incoming nucleotide stabilization, especially required during primer synthesis. Glu-119 is required to stabilize the incoming nucleotide at the 3'-site. Belongs to the eukaryotic-type primase small subunit family.