Dim2p, a KH-domain protein required for small ribosomal subunit synthesis

RNA. 2004 Apr;10(4):645-56. doi: 10.1261/rna.5162204.


Recent proteomic analyses are revealing the dynamics of preribosome assembly. Following cleavage at processing site A(2), which generates the 20S pre-rRNA (the immediate precursor to the 18S rRNA), early RRPs (ribosomal RNA processing factors) are released in bulk from the preribosomes, and the resulting pre-40S subunits are left associated with a limited set of proteins that we refer to as the SSU RRP complex. Dim2p, a core constituent of the SSU RRP complex and conserved KH-domain containing protein, is required for pre-rRNA processing and is associated with early nucleolar and late cytoplasmic pre-rRNA species. Consistently, Dim2p shuttles between the nucle(ol)us and the cytoplasm, a trafficking that is tightly regulated by growth. The association of Dim2p with the 18S rRNA dimethyltransferase Dim1p, as well as its requirement for pre-rRNA processing at cleavage sites A(1) and A(2) and for 18S rRNA dimethylation, suggest that Dim2p may recruit Dim1p to nucleolar pre-rRNAs through its KH domain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleolus / metabolism
  • Cytoplasm / metabolism
  • Phylogeny
  • Protein Structure, Tertiary
  • RNA Precursors / metabolism*
  • RNA Processing, Post-Transcriptional*
  • RNA, Ribosomal, 18S / biosynthesis*
  • RNA-Binding Proteins / genetics
  • Ribosomes / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Yeasts / genetics
  • Yeasts / metabolism


  • DIM2 protein, S cerevisiae
  • KRR1 protein, S cerevisiae
  • RNA Precursors
  • RNA, Ribosomal, 18S
  • RNA-Binding Proteins
  • Saccharomyces cerevisiae Proteins