Alpha-internexin has a homologous central rod domain of approximately 310 amino acid residues that form a highly conserved alpha helical region. The central rod domain is responsible for coiled-coil structure and is flanked by an amino terminal head region and a carboxy terminal tail. This rod domain is also involved in the 10 nm filament assembly structure. The head and tail regions contain segments that are highly homologous to the NF-M’s structure. The head region is highly basic and contains many serine and threonine polymers while the tail region has distinct sequence motifs like a glutamate rich region. The alpha domain is composed of heptad repeats of hydrophobic residues that aid the formation of a coiled coil structure. The structure of Alpha-internexin is highly conserved between rats, mice and humans.