The two amino acids most often found in a polyproline II helix are proline and _______.
A)alanine
B)glycine
C)serine
D)lysine
E)histidine

Question

Quizplus · Accepted Answer

Polyproline II helix is a type of secondary structure that is stabilized by the presence of cis peptide bonds. Because of the nature of proline's side chain, it is often found in cis conformation in polyproline II helix. Glycine is the other amino acid that can adopt cis conformation due to its small side chain. Therefore, proline and glycine are the two amino acids most often found in polyproline II helix.

The Two Amino Acids Most Often Found in a Polyproline