Proline is one of the twenty amino acids that are used by living organisms as a building block of proteins. Technically, proline is an imino acid, as it contains no amino group.
In proteins, proline can act as a structural disruptor for α helices, and as a turning point in β sheets. Multiple prolines in a row can create a proline helix.
... will cause one end of the axis to push against the upper rim of the groove, while the other end of the axis pushes against the lower rim of the groove. While the axis i ...