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 (By similarity). 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. Interacts with FAAP20 (By similarity). The C-terminal domain is necessary for protein interactions. Belongs to the DNA polymerase type-Y family.