The presence of these structures can be identified on hydrophilicity (15[1])or hydrophobicity plots by a stretch of 20 positive values on the Kyte–Doolittle (15[1])scale. A double (15[1])minimum at 208 and 222 nanometers in circular dichroism spectroscopy is used to identify these structures. (15[2])These structures have square-like cross sections that allow them to be differentiated from similar structures named for “310” (-5[1])and pi. Two of these structures are dimerized in the DNA-binding leucine zipper motif. (*) Glycine and proline are called “breakers” of these structures. (10[1])A diagonal cluster on Ramachandran plots around dihedral angles (-5[1])of −60 (“negative 60”) and −45 (“negative 45”) degrees identifies these structures. Hydrogen bonds stabilize the 3.6 residues per turn (10[1])characteristic of these structures. For 10 points, name this (10[1])coiled secondary structure motif in proteins that is more common than beta sheets. ■END■ (10[1])