Structural domains comprising this superfamily share the structure of the linker region of the DNA integrity scanning protein A (DisA), a bacterial checkpoint protein that dimerises into an octameric complex. The protein consists of three distinct domains with the linker region corresponds to domain 2. This domain is comprised by an elongated bundle of three alpha helices, one side of of the bundle is decorated by an insertion of three additional helices, structure which allows the formation of a spine like-linker between domains 1 and 3 PMID:18439896.