Pentapeptide repeats are a family of sequence motifs found in multiple tandem copies in protein molecules.

[4] The later Bateman et al. showed that a large family of related pentapeptide repeat proteins existed.

[5] The repeats form a regular right handed four sided beta helix structure known as the Rfr-fold.

Pentapeptide repeats were initially predicted from sequence to possess a right handed beta helix with three sides.

It showed that pentapeptide repeat proteins (PRPs) possessed a four sided beta helix structure.