The Slx4 protein is a heteromeric structure-specific endonuclease found from fungi to mammals. Slx4 with Slx1 acts as a nuclease on branched DNA substrates, particularly simple-Y, 5'-flap, or replication fork structures by cleaving the strand bearing the 5' non-homologous arm at the branch junction and thus generating ligatable nicked products from 5'-flap or replication fork substrates [1].

1: Slx1-Slx4 is a second structure-specific endonuclease functionally redundant with Sgs1-Top3. Fricke WM, Brill SJ; Genes Dev. 2003;17:1768-1778. PMID:12832395

2: Coordination of structure-specific nucleases by human SLX4/BTBD12 is required for DNA repair. Munoz IM, Hain K, Declais AC, Gardiner M, Toh GW, Sanchez-Pulido L, Heuckmann JM, Toth R, Macartney T, Eppink B, Kanaar R, Ponting CP, Lilley DM, Rouse J; Mol Cell. 2009;35:116-127. PMID:19595721

3: Human SLX4 is a Holliday junction resolvase subunit that binds multiple DNA repair/recombination endonucleases. Fekairi S, Scaglione S, Chahwan C, Taylor ER, Tissier A, Coulon S, Dong MQ, Ruse C, Yates JR 3rd, Russell P, Fuchs RP, McGowan CH, Gaillard PH; Cell. 2009;138:78-89. PMID:19596236

4: Mutations of the SLX4 gene in Fanconi anemia. Kim Y, Lach FP, Desetty R, Hanenberg H, Auerbach AD, Smogorzewska A; Nat Genet. 2011;43:142-146. PMID:21240275

5: Mutation analysis of the SLX4/FANCP gene in hereditary breast cancer. Landwehr R, Bogdanova NV, Antonenkova N, Meyer A, Bremer M, Park-Simon TW, Hillemanns P, Karstens JH, Schindler D, Dork T; Breast Cancer Res Treat. 2011;130:1021-1028. Cell. 2009;138:78-89. PMID:21805310