Single-stranded DNA-stimulated ATPase involved in DNA double- strand break (DSB) repair via homologous recombination (HR) (PubMed:21965664, PubMed:34253720, PubMed:39169038, PubMed:40345587). Forms a heterodimeric complex with ZSWIM7/SWS1 that promotes HR by regulating replication protein-A (RPA) dynamics on single-stranded DNA, thereby stabilizing RAD51 and DMC1 filaments on DNA (PubMed:34253720, PubMed:39169038, PubMed:40345587). The SWSAP1-ZSWIM7/SWS1 heterodimer is essential during meiosis by stabilizing DMC1 filaments (By similarity). In contrast, it is critical for only certain types of homologous-directed DNA repair, such as inter-homolog homologous recombination (IR-HR) (PubMed:34253720). IR-HR is a DNA repair mechanism where a cell repairs a DSB on one chromosome using the matching homologous chromosome as a template, rather than the sister chromatid (PubMed:34253720). Also promotes homologous recombination by inactivating the FIGNL1-FIRRM complex to protect RAD51 filament from premature disassembly (PubMed:30926776). Has a DNA-binding activity which is independent of its ATPase activity: preferentially binds DNA with an exposed 5' end (PubMed:40345587). {ECO:0000250|UniProtKB:Q8VCI7, ECO:0000269|PubMed:21965664, ECO:0000269|PubMed:30926776, ECO:0000269|PubMed:34253720, ECO:0000269|PubMed:39169038, ECO:0000269|PubMed:40345587}. This is the function of ENSG00000173928 (SWSAP1, SWIM-type zinc finger 7 associated protein 1).