The FtsJ/RrmJ heat shock protein of Escherichia coli is a 23 S ribosomal RNA methyltransferase

J Biol Chem. 2000 Jun 2;275(22):16414-9. doi: 10.1074/jbc.M001854200.


Ribosomal RNAs undergo several nucleotide modifications including methylation. We identify FtsJ, the first encoded protein of the ftsJ-hflB heat shock operon, as an Escherichia coli methyltransferase of the 23 S rRNA. The methylation reaction requires S-adenosylmethionine as donor of methyl groups, purified FtsJ or a S(150) supernatant from an FtsJ-producing strain, and ribosomes from an FtsJ-deficient strain. In vitro, FtsJ does not efficiently methylate ribosomes purified from a strain producing FtsJ, suggesting that these ribosomes are already methylated in vivo by FtsJ. FtsJ is active on ribosomes and on the 50 S ribosomal subunit, but is inactive on free rRNA, suggesting that its natural substrate is ribosomes or a pre-ribosomal ribonucleoprotein particle. We identified the methylated nucleotide as 2'-O-methyluridine 2552, by reverse phase high performance liquid chromatography analysis, boronate affinity chromatography, and hybridization-protection experiments. In view of its newly established function, FtsJ is renamed RrmJ and its encoding gene, rrmJ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism*
  • Chromatography, High Pressure Liquid
  • DNA Primers
  • Escherichia coli / metabolism*
  • Methyltransferases / chemistry
  • Methyltransferases / metabolism*


  • Bacterial Proteins
  • Cell Cycle Proteins
  • DNA Primers
  • Methyltransferases
  • rlmE protein, E coli
  • rRNA (adenosine-O-2'-)methyltransferase