Dip2 proteins show sequence similarity to other members of the adenylate forming enzyme family, including insect luciferase, acetyl CoA ligases and the adenylation domain of nonribosomal peptide synthetases (NRPS) [, , , ]. However, its function may have diverged from other members of the superfamily. In mouse embryo, Dip2 homologue A plays an important role in the development of both vertebrate and invertebrate nervous systems. Dip2A appears to regulate cell growth and the arrangement of cells in organs. Biochemically, Dip2A functions as a receptor of FSTL1, an extracellular glycoprotein, and may play a role as a cardiovascular protective agent [, ].According to bioinformatics analysis DIP2A is a type I receptor molecule with three domains from the N to the C terminus: the DNA methyltransferase 1 associated protein (DMAP)-binding domain, CaiC, and adenosine monophosphate (AMP)-binding domain. This entry corresponds to the CaiC domain of Dip2. The CaiC domain also binds AMP and is found in acyl CoA synthetases and AMP-acid ligases that are involved in lipid metabolism, secondary metabolite biosynthesis, transport and catabolism [].
