Visualizing maturation factor extraction from the nascent ribosome by the AAA-ATPase Drg1

Nat Struct Mol Biol. 2022 Sep;29(9):942-953. doi: 10.1038/s41594-022-00832-5. Epub 2022 Sep 12.


The AAA-ATPase Drg1 is a key factor in eukaryotic ribosome biogenesis that initiates cytoplasmic maturation of the large ribosomal subunit. Drg1 releases the shuttling maturation factor Rlp24 from pre-60S particles shortly after nuclear export, a strict requirement for downstream maturation. The molecular mechanism of release remained elusive. Here, we report a series of cryo-EM structures that captured the extraction of Rlp24 from pre-60S particles by Saccharomyces cerevisiae Drg1. These structures reveal that Arx1 and the eukaryote-specific rRNA expansion segment ES27 form a joint docking platform that positions Drg1 for efficient extraction of Rlp24 from the pre-ribosome. The tips of the Drg1 N domains thereby guide the Rlp24 C terminus into the central pore of the Drg1 hexamer, enabling extraction by a hand-over-hand translocation mechanism. Our results uncover substrate recognition and processing by Drg1 step by step and provide a comprehensive mechanistic picture of the conserved modus operandi of AAA-ATPases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Adenosine Triphosphatases / metabolism*
  • Ribosomal Proteins / metabolism
  • Ribosome Subunits, Large, Eukaryotic / metabolism
  • Ribosomes / metabolism
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / metabolism*


  • Arx1 protein, S cerevisiae
  • Ribosomal Proteins
  • Saccharomyces cerevisiae Proteins
  • Adenosine Triphosphatases
  • AFG2 protein, S cerevisiae
  • ATPases Associated with Diverse Cellular Activities