This family represents the hinge region of the SMC (Structural Maintenance of Chromosomes) family of proteins. The hinge region is responsible for formation of the DNA interacting dimer. It is also possible that the precise structure of it is an essential determinant of the specificity of the DNA-protein interaction ([1]).

1: Hinge-mediated dimerization of SMC protein is essential for its dynamic interaction with DNA. Hirano M, Hirano T; EMBO J 2002;21:5733-5744. PMID:12411491