FtsA is essential for bacterial cell division, and co-localises to the septal ring with FtsZ. It has been suggested that the interaction of FtsA-FtsZ has arisen through coevolution in different bacterial strains [1]. The FtsA protein contains two structurally related actin-like ATPase domains which are also structurally related to the ATPase domains of HSP70 (see PF00012). FtsA has a SHS2 domain PF02491 inserted in to the RnaseH fold PF02491 [2].

1: Interactions between heterologous FtsA and FtsZ proteins at the FtsZ ring. Ma X, Sun Q, Wang R, Singh G, Jonietz EL, Margolin W; J Bacteriol 1997;179:6788-6797. PMID:9352931

2: The SHS2 module is a common structural theme in functionally diverse protein groups, like Rpb7p, FtsA, GyrI, and MTH1598/TM1083 superfamilies. Anantharaman V, Aravind L; Proteins. 2004;56:795-807. PMID:15281131