Topological characteristics of helical repeat protein

The recent elucidation of protein structures based upon repeating amino acid motifs, including the armadillo motif, the HEAT motif and tetratricopeptide repeats, reveals that they belong to the class of helical repeat proteins. These proteins share the common property of being assembled from tandem repeats of an α-helical structural unit, creating extended superhelical structures that are ideally suited to create a protein recognition interface.