This family of proteins contain a conserved 60 residue region. This protein is known as ChaB in E. coli and is found next to ChaA which is a cation transporter protein. ChaB may be regulate ChaA function in some way.

1: Expression of chaA, a sodium ion extrusion system of Escherichia coli, is regulated by osmolarity and pH. Shijuku T, Yamashino T, Ohashi H, Saito H, Kakegawa T, Ohta M, Kobayashi H; Biochim Biophys Acta 2002;1556:142-148. PMID:12460671