Three mechanisms in Escherichia coli rescue ribosomes stalled on non-stop mRNAs: one of them requires release factor 2.
The tmRNA/SmpB system, which is almost universal in bacteria, rescues bacterial ribosomes stalled at the end of non-stop mRNAs (mRNAs lacking a stop codon). In addition, a few bacteria, including Escherichia coli, have developed a second two-component system as reported by Chadani et al. (2012). A small protein, ArfA of 55 amino acids (formerly called YdhL), mediates binding of release factor 2 to the ribosomal A site lacking a complete mRNA codon and thereby triggers translational termination and rescue of the stalled ribosome.
Max-Planck-Institut für Molekulare Genetik, Abteilung Vingron, AG Ribosomen, Ihnestr. 73, D-14195, Berlin, Germany.
Markus
M
Pech
Knud H
KH
Nierhaus
D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D010454:Peptide Termination Factors / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
C556014:ArfA protein, E coli; D029968:Escherichia coli Proteins; D010454:Peptide Termination Factors; D012346:RNA, Transfer, Amino Acyl; D016601:RNA-Binding Proteins; C489006:prfB protein, E coli; C019037:tRNA, peptidyl-