RqcH and RqcP catalyze processive poly-alanine synthesis in a reconstituted ribosome-associated quality control system.

ABSTRACT: In the cell, stalled ribosomes are rescued through ribosome-associated protein quality-control (RQC) pathways. After splitting of the stalled ribosome, a C-terminal polyalanine 'tail' is added to the unfinished polypeptide attached to the tRNA on the 50S ribosomal subunit. In Bacillus subtilis, polyalanine tailing is catalyzed by the NEMF family protein RqcH, in cooperation with RqcP. However, the mechanistic details of this process remain unclear. Here we demonstrate that RqcH is responsible for tRNAAla selection during RQC elongation, whereas RqcP lacks any tRNA specificity. The ribosomal protein uL11 is crucial for RqcH, but not RqcP, recruitment to the 50S subunit, and B. subtilis lacking uL11 are RQC-deficient. Through mutational mapping, we identify critical residues within RqcH and

SUBMITTER: Takada H 

PROVIDER: S-EPMC8373112 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature