Members of this family adopt a secondary structure consisting of an open-face beta/alpha sandwich, with four antiparallel beta-strands and two alpha-helices. They bind to a corresponding domain on CheY, with subsequent phosphorylation of the CheY Asp57 residue, and activation of CheY, which then affects flagellar rotation [1].

1: Further insights into the mechanism of function of the response regulator CheY from crystallographic studies of the CheY--CheA(124--257) complex. Gouet P, Chinardet N, Welch M, Guillet V, Cabantous S, Birck C, Mourey L, Samama JP; Acta Crystallogr D Biol Crystallogr. 2001;57:44-51. PMID:11134926