Domain organization (A) and primary structure (B) of the Macif1 protein. Hydrophobic residues are shown in black, hydrophilic residues in green, acidic residues in red and basic residues in blue. The characteristic heptad repeat pattern is shown as “abcdefg” and the apolar residues located at position “a” and “d” are indicated in yellow. The linker L2 that separates the coils 2A and 2B in vertebrate intermediate filaments is highlighted in grey. See text for more details.