Site-directed and deletion mutagenesis and plasmid construction. Deletion mutagenesis was carried out with pairs of primers against domains of interest described in the figure legends. PCR products were subcloned into pGEX-KG [64], HybriZAP pBD-GAL4 vector (Stratagene), and pBUTE [62] vectors. GST-LDZIP alone comprised residues 447–483 of human RanBP2.