FtsK has extensive sequence similarity to wide variety of proteins from prokaryotes and plasmids, termed the FtsK/SpoIIIE family. This domain contains a putative ATP binding P-loop motif. It is found in the FtsK cell division protein from E. coli and the stage III sporulation protein E SpoIIIE which has roles in regulation of prespore specific gene expression in B. subtilis. A mutation in FtsK causes a temperature sensitive block in cell division and it is involved in peptidoglycan synthesis or modification. The SpoIIIE protein is implicated in intercellular chromosomal DNA transfer.