Secondary Structures and their Average Ramachandran Angles

This is derived from Flory, P.J., Statistical Mechanics of Chain Molecules, p. 253, Interscience (1969); and IUPAC-IUB Commission on Biochemical Nomenclature, Biochemistry 9, 3475 (1970)

Right-handed alpha helix

phi: -57, psi: -47

Parallel beta pleated sheet

phi: -119, psi: 113

Antiparallel beta pleated sheet

phi: -139, psi: 135

Right-handed 3₁₀ helix

phi: -49, psi: -26

Right-handed pi helix

phi: -57, psi: -70

2.2₇ ribbon

phi: -78, psi: 59

Left-handed polyglycine II and poly-L-proline II helices

phi: -79, psi: 150

Collagen

phi: -51, psi: 153

Left-handed alpha helix

phi: 57, psi: 47