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 hypothesised that the N-terminal domain of NS5 is a methyltransferase involved in viral RNA capping .
This entry represents FtsJ domain. RrmJ (FtsJ) is a well conserved heat shock protein present in prokaryotes, archaea, and eukaryotes. RrmJ is responsible for methylating 23 S rRNA at position U2552 in the aminoacyl (A)1-site of the ribosome [PUBMED:11976298]. U2552 is one of the five universally conserved A-loop residues and has been shown to be methylated at the ribose 2'-OH group in the majority of organisms investigated so far. This suggests that this modification plays an important role in the A-loop function. RrmJ recognises its methylation target only when the 23 S rRNA is present in 50 S ribosomal subunits. This suggests that the RrmJ-mediated methylation must occur late in the maturation process of the ribosome. This is in contrast to other known 23 S rRNA modifications that occur in earlier maturation steps.
Koonin EV; , J Gen Virol 1993;74:733-740.: Computer-assisted identification of a putative methyltransferase domain in NS5 protein of flaviviruses and lambda 2 protein of reovirus. PUBMED:8385698 EPMC:8385698.