Replisome component that maintains genome stability by protecting stalled or damaged replication forks. After the induction of replication stress, required for the stabilization of stalled replication forks, the efficient activation of the intra-S-phase and G/2M cell-cycle checkpoints and the maintenance of genome stability. Component of the replisome complex composed of at least MCM2, MCM7, PCNA and TICRR; interaction at least with PCNA occurs during DNA replication. Localizes at DNA replication sites. At 14.5 dpc, widely expressed, including in neocortex, cerebellum, lung, liver, hindlimb, intestine, as well as forelimb, kidney and spinal cord vertebrae. Early embryonic lethality. Heterozygous mice show no overt phenotype. Belongs to the DONSON family.