Chaperone protein SycN is part of the type III secretion system and functions as a specific chaperone for YopN which may facilitate the secretion and the subsequent translocation of YopN [1].

1: Three-dimensional structure of a macromolecular assembly that regulates type III secretion in Yersinia pestis. Schubot FD, Jackson MW, Penrose KJ, Cherry S, Tropea JE, Plano GV, Waugh DS; J Mol Biol. 2005;346:1147-1161. PMID:15701523