In an ? helix, each amino acid residue is rotated by about +100° and raised by about 0.15 nm relative to the previous residue. This means that each full turn of the helix rises by … nm parallel to the helix's axis.

Question

Quizplus · Accepted Answer

A full (360°) turn in the ? helix contains 3.6 residues (360°/[100° per residue]), and is thus raised by 0.54 nm:
3.6 residues per turn × 0.15 nm rise per residue = 0.54 nm rise per turn.

In an ? Helix, Each Amino Acid Residue Is Rotated