InterPro domain: IPR036886

Villin is an F-actin bundling protein involved in themaintenance of the microvilli of the absorptive epithelia. The villin-type "headpiece" domain is a modular motif found at the extreme C terminus of larger "core" domains in over 25 cytoskeletal proteins in plants and animals, often in assocation with the Gelsolin repeat. Although the headpiece is classified as an F-actin-binding domain, it has been shown that not all headpiece domains are intrinsically F-actin-binding motifs, surface charge distribution may be an important element for F-actin recognition [ 1 ]. An autonomously folding, 35 residue, thermostable subdomain (HP36) of the full-length 76 amino acid residue villin headpiece, is the smallest known example of a cooperatively folded domain of a naturally occurring protein. The structure of HP36, as determined by NMR spectroscopy, consists of three short helices surrounding a tightly packed hydrophobic core [ 2 ].

1. Villin-type headpiece domains show a wide range of F-actin-binding affinities. Cell Motil. Cytoskeleton 52, 9-21
2. Temperature-dependent dynamics of the villin headpiece helical subdomain, an unusually small thermostable protein. J. Mol. Biol. 320, 841-54