Fusion protein amino acids 772-992 (C-terminus) of rat SAPAP1 (also known as disks large-associated protein 1, guanylate kinase-associated protein, GKAP, SAP90/PSD-95-associated/binding protein 1, accession number P97836) Mouse: 99% identity (200/201 amino acids identical) Human: 99% identity (199/201 amino acids identical) 55-65% identity with other SAPAPs