Structural domains comprising this superfamily share the structure of SsgB, a conserved activator of developmental cell division in morphologically complex actinomycetes. It controls cell division and spore maturation in streptomycetes. Together with SsgA, SsgB activates sporulation-specific cell division by controlling the localisation of FtsZ PMID:26002075. SsgB shows structural similarity to whirly ssDNA/guide RNA-binding proteins found in mitochondria or in plants, but the interaction of this protein with nucleic acids is unlikely. On the other hand, a conserved surface for protein-protein interaction has been identified and search for different interacting partners is being conducted PMID:19567872.