Functions as a modulator of initiation or reinitiation events during DNA polymerase delta-mediated DNA synthesis. In the presence of ATP, stimulation of DNA polymerase delta-mediated DNA synthesis is decreased. Also plays a role in the innate immune defense against viruses. Stabilizes the RIG-I/DDX58 dsRNA interaction and promotes RIG-I/DDX58 'Lys-63'-linked polyubiquitination. In turn, RIG-I/DDX58 transmits the signal through mitochondrial MAVS. ATP + H2O = ADP + H(+) + phosphate Forms homooligomers (PubMed:18842586), possibly octamers. Directly interacts with POLD1, POLD2 and POLD4 (PubMed:15670210). Interacts with the N-terminal domain of WRN (By similarity). Interacts (via UBZ4-type zinc finger) with monoubiquitin and polyubiquitin (PubMed:17550899, PubMed:18842586). Interacts with TRIM14 and PPP6C; these interactions positively regulate the RIG-I/DDX58 signaling pathway (PubMed:29053956). Colocalizes with WRN in granular structures in the nucleus. Ubiquitously expressed. The UBZ4-type zinc finger binds ubiquitin. Sumoylated with SUMO1 and SUMO2/3. Belongs to the AAA ATPase family. RarA/MGS1/WRNIP1 subfamily.