Here we report the creation of a predominantly beta -structured mini-protei
n moth. The design target is based on the naturally occurring toxin hand (T
H) moths that are composed of four disulfide bonds and three loops that for
m a 'hand: Analysis and subsequent modification of several generations of m
ini-proteins produced the final 29-residue mini-protein, The structured mot
h of this new mini-protein provides insight into the compensatory changes t
hat result in the formation of a tightly packed hydrophobic core in a small
, globular beta -structure moth. Additionally, this mini-motif represents a
new, distinct surface topology for protein design and a valuable, yet comp
act, model system for the study of beta -sheet structure in water.