What is "villin"

Villin is a 92.5 kDa tissue-specific actin-binding protein associated with the actin core bundle of the brush border. Villin contains multiple gelsolin-like domains capped by a small (8.5 kDa) "headpiece" at the C-terminus consisting of a fast and independently folding three-helix bundle that is stabilized by hydrophobic interactions. The headpiece domain is a commonly studied protein in molecular dynamics due to its small size and fast folding kinetics and short primary sequence.