Modular domain structures of neuronal SNAREs and related regulatory proteins. Rat protein sequences and isoforms are shown. The sequence lengths of these proteins are shown to scale, except that the scale of the last three proteins is five times smaller than the scale of the first five proteins. SNARE, SNARE motif; TM, transmembrane domain; N-pep, N-terminal peptide (residues 1-10); Habc, Habc regulatory domain of syntaxin (residues 27-146); CCCC, palmitoylated cysteines; NT, N-terminal (1-12); AH, accessory helix (28-47); CH, central helix (48-70); CT, C-terminal (114-134); NTR, N-terminal region (1-25); CR, central region (26-97); NAC, non-amyloid-β component (61-95); CTR, C-terminal region (98-140); CaMb, calmodulin binding region (459-492); MUN, MUN domain (859-1531).