Members of this family consist of a beta-sheet region followed by an alpha-helix and an unstructured C-terminus. The beta-sheet region contains a CXCX...XCXC sequence with Cys residues located in two proximal loops and pointing towards each other. This precise function of this set of bacterial proteins is, as yet, unknown [1].

1: Structural proteomics of an archaeon. Christendat D, Yee A, Dharamsi A, Kluger Y, Savchenko A, Cort JR, Booth V, Mackereth CD, Saridakis V, Ekiel I, Kozlov G, Maxwell KL, Wu N, McIntosh LP, Gehring K, Kennedy MA, Davidson AR, Pai EF, Gerstein M, Edwards AM, Arrowsmith CH; Nat Struct Biol 2000;7:903-909. PMID:11017201