<p>Spectrin repeats [<cite idref="PUB00005178"/>] are found in several proteins involved in cytoskeletal structure. These include spectrin alpha and beta subunits [<cite idref="PUB00029619"/>, <cite idref="PUB00030886"/>], alpha-actinin [<cite idref="PUB00030394"/>] and dystrophin. The spectrin repeat forms a three-helix bundle. The second helix is interrupted by proline in some sequences. The repeats are defined by a characteristic tryptophan (W) residue at position 17 in helix A and a leucine (L) at 2 residues from the carboxyl end of helix C.</p> Spectrin/alpha-actinin