RNA cytidine acetyltransferase of small-subunit ribosomal RNA: identification of acetylation sites and the responsible acetyltransferase in fission yeast, Schizosaccharomyces pombe

PLoS One. 2014 Nov 17;9(11):e112156. doi: 10.1371/journal.pone.0112156. eCollection 2014.


The eukaryotic small-subunit (SSU) ribosomal RNA (rRNA) has two evolutionarily conserved acetylcytidines. However, the acetylation sites and the acetyltransferase responsible for the acetylation have not been identified. We performed a comprehensive MS-based analysis covering the entire sequence of the fission yeast, Schizosaccharomyces pombe, SSU rRNA and identified two acetylcytidines at positions 1297 and 1815 in the 3' half of the rRNA. To identify the enzyme responsible for the cytidine acetylation, we searched for an S. pombe gene homologous to TmcA, a bacterial tRNA N-acetyltransferase, and found one potential candidate, Nat10. A temperature-sensitive strain of Nat10 with a mutation in the Walker A type ATP-binding motif abolished the cytidine acetylation in SSU rRNA, and the wild-type Nat10 supplemented to this strain recovered the acetylation, providing evidence that Nat10 is necessary for acetylation of SSU rRNA. The Nat10 mutant strain showed a slow-growth phenotype and was defective in forming the SSU rRNA from the precursor RNA, suggesting that cytidine acetylation is necessary for ribosome assembly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Cytidine / metabolism
  • Mutation
  • N-Terminal Acetyltransferase E / genetics
  • N-Terminal Acetyltransferase E / metabolism
  • RNA Processing, Post-Transcriptional*
  • RNA, Ribosomal, 18S / genetics*
  • RNA, Ribosomal, 18S / metabolism*
  • Ribosome Subunits, Small, Eukaryotic / genetics*
  • Ribosome Subunits, Small, Eukaryotic / metabolism*
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / metabolism*


  • RNA, Ribosomal, 18S
  • Cytidine
  • N-Terminal Acetyltransferase E

Grant support

This work was supported by Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.