Structural basis for bacterial ribosome quality control [article]

Caillan Crowe-McAuliffe, Hiraku Takada, Victoriia Murina, Christine Polte, Sergo Kasvandik, Tanel Tenson, Zoya Ignatova, Gemma C. Atkinson, Daniel N. Wilson, Vasili Hauryliuk
2020 bioRxiv   pre-print
SummaryIn all branches of life, stalled translation intermediates are recognized and processed by ribosome-associated quality-control (RQC) pathways. RQC begins with splitting of stalled ribosomes, leaving an unfinished polypeptide still attached to the large subunit. Ancient and conserved NEMF family RQC proteins target these incomplete proteins for degradation by the addition of C-terminal 'tails.' How such tailing can occur without the regular suite of translational components is, however,
more » ... ents is, however, unclear. Using ex vivo single-particle cryo-EM, we show that C-terminal tailing in Bacillus subtilis is mediated by NEMF protein RqcH in concert with YabO, a protein homologous to, yet distinct from, Hsp15. Our structures reveal how these factors mediate tRNA movement across the ribosomal 50S subunit to synthesize polypeptides in the absence of mRNA or the small subunit.
doi:10.1101/2020.09.03.281279 fatcat:eyabuzbhmrgj5os657w5bcabqy