beta-turn

since type II beta-turn signal can predict strandon,
it means there do exist pattern in sequences at the turn.
this tells us we also need to analysis the turn, not only the strands.

Type II'. The first residue of these turns has a conformation which can only be adopted by glycine (see below Ramachandran plot). The second residue shows a preference for polar amino acids such as serine and threonine.