YaeJ is a novel ribosome-associated protein in Escherichia coli that can hydrolyze peptidyl-tRNA on stalled ribosomes.

ABSTRACT: In bacteria, ribosomes often become stalled and are released by a trans-translation process mediated by transfer-messenger RNA (tmRNA). In the absence of tmRNA, however, there is evidence that stalled ribosomes are released from non-stop mRNAs. Here, we show a novel ribosome rescue system mediated by a small basic protein, YaeJ, from Escherichia coli, which is similar in sequence and structure to the catalytic domain 3 of polypeptide chain release factor (RF). In vitro translation experiments using the E. coli-based reconstituted cell-free protein synthesis system revealed that YaeJ can hydrolyze peptidyl-tRNA on ribosomes stalled by both non-stop mRNAs and mRNAs containing rare codon clusters that extend downstream from the P-site and prevent Ala-tmRNA•SmpB from entering the empty A-site.

SUBMITTER: Handa Y 

PROVIDER: S-EPMC3061065 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature