Membrane-attachment and polymerization-promoting switch
This family is the C-terminal region of essential streptococcal FtsA proteins and their homologs. It acts as an intra-molecular switch, triggered by ATP, to promote polymerization of the whole protein and to attach it to the membrane. FtsA is essential for the formation of the septum that divides fully-grown cells into two daughter cells at cell-division. FtsA anchors the constricting FtsZ ring to the membrane.