This domain is found in proteins from Mycoplasmaceae, including Uncharacterized protein MG281 from Mycoplasma genitalium, also known as protein M. This virulence protein consists of two domains. The larger one (this entry) binds the IgG light chain to block the binding of antibody to antigen. It includes a leucine-rich repeat (LRR)-like subdomain, which faces away from the antibody molecule [1].

1: A structurally distinct human mycoplasma protein that generically blocks antigen-antibody union. Grover RK, Zhu X, Nieusma T, Jones T, Boreo I, MacLeod AS, Mark A, Niessen S, Kim HJ, Kong L, Assad-Garcia N, Kwon K, Chesi M, Smider VV, Salomon DR, Jelinek DF, Kyle RA, Pyles RB, Glass JI, Ward AB, Wilson IA, Lerner RA; Science. 2014;343:656-661. PMID:24503852