This family consists of FtsJ from various bacterial and archaeal sources FtsJ is a methyltransferase, but actually has no effect on cell division. FtsJ's substrate is the 23S rRNA. The 1.5 A crystal structure of FtsJ in complex with its cofactor S-adenosylmethionine revealed that FtsJ has a methyltransferase fold. This family also includes the N-terminus of flaviviral NS5 protein. It has been hypothesized that the N-terminal domain of NS5 is a methyltransferase involved in viral RNA capping.