Deoxycytidyl transferase involved in DNA repair. Transfers a dCMP residue from dCTP to the 3'-end of a DNA primer in a template-dependent reaction. May assist in the first step in the bypass of abasic lesions by the insertion of a nucleotide opposite the lesion. Required for normal induction of mutations by physical and chemical agents. Monomer. Interacts with the DNA polymerase zeta which is composed of REV3L and MAD2L2; the interaction with MAD2L2 is direct and requires that REV3L is in its closed conformation. Interacts with POLH, POLI and POLK. May bind ITGA3. Interacts with FAAP20/C1orf86. Ubiquitous. The C-terminal domain is necessary for protein interactions. Belongs to the DNA polymerase type-Y family.