This domain is found at the C-terminus of adenylosuccinate lyase(ASL; PurB in E. coli). It has been identified in bacteria, eukaryotes and archaea and is found together with the lyase domain Pfam:PF00206. ASL catalyses the cleavage of succinylaminoimidazole carboxamide ribotide to aminoimidazole carboxamide ribotide and fumarate and the cleavage of adenylosuccinate to adenylate and fumarate [1].

1: Characterization of the cDNA and the gene encoding murine adenylosuccinate lyase. Wong LJ, O'Brien WE; Genomics 1995;28:341-343. PMID:8530047