Armadillo repeat

An armadillo repeat is a characteristic, repetitive amino acid sequence of about 42 residues in length that is found in many proteins.

[2][3] Each armadillo repeat is composed of a pair of alpha helices that form a hairpin structure.

Examples of proteins that contain armadillo repeats include β-catenin, Sarm1 (SARM1),[4] α-importin,[5] plakoglobin,[6] adenomatous polyposis coli (APC),[7] and many others.

Although β-catenin was previously believed to be a protein involved in linking cadherin cell adhesion proteins to the cytoskeleton, recent work indicates that β-catenin regulates the homodimerization of alpha-catenin, which in turn controls actin branching and bundling.

This type of protein domain is important in transducing WNT signals during embryonic development.