HEAT repeats

a domain of ~40 amino acids named after the first four proteins in which it was discovered: Huntingtin, Elongation factor 3, a subunit of protein phosphatase 2A and the lipid kinase TOR. Although the exact function of HEAT repeats are currently unclear, studies have suggested that these domains play a role in a variety of interactions between proteins, including transportation in the cytoplasm and nucleus, microtubule dynamics and chromosome separation.