Concurrent remodelling of nucleolar 60S subunit precursors by the Rea1 ATPase and Spb4 RNA helicase.

ABSTRACT: Biogenesis intermediates of nucleolar ribosomal 60S precursor particles undergo a number of structural maturation steps before they transit to the nucleoplasm and are finally exported into the cytoplasm. The AAA⁺-ATPase Rea1 participates in the nucleolar exit by releasing the Ytm1-Erb1 heterodimer from the evolving pre-60S particle. Here, we show that the DEAD-box RNA helicase Spb4 with its interacting partner Rrp17 is further integrated into this maturation event. Spb4 binds to a specific class of late nucleolar pre-60S intermediates, whose cryo-EM structure revealed how its helicase activity facilitates melting and restructuring of 25S rRNA helices H62 and H63/H63a prior to Ytm1-Erb1 release. In vitro maturation of such Spb4-enriched pre-60S particles, incubated with purified

SUBMITTER: Mitterer V 

PROVIDER: S-EPMC10154028 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature