Results of the protein family (Pfam) analysis showing the domains in NTE. Numbering corresponds to amino acid residues at the N- and C- termini of each domain. As shown, NTE consists of a single N-terminal transmembrane domain (TMD; residues 9–31), three cyclic nucleotide domains (CNP domains; residues 163–262, 480–573 and 597–689), and a patatin homology domain (PNTE, residues 933–1099) containing its active site.