After TmRNA Releases an MRNA and Aberrant Polypeptide from a Stuck

Question

After tmRNA releases an mRNA and aberrant polypeptide from a stuck ribosome,
A) clpX tags the peptide for destruction.
B) sspB tags the peptide for destruction.
C) tmRNA then destroys the peptide.
D) tmRNA ubiquitinates the peptide.
E) sspB recognizes a proteolysis tag and delivers the peptide to clpX for degradation.

Accepted Answer

After tmRNA releases an mRNA and aberrant polypeptide from a stuck ribosome, sspB recognizes a proteolysis tag and delivers the peptide to clpX for degradation, where it is ultimately destroyed. tmRNA does not directly destroy the peptide, nor does it ubiquitinate it. Therefore, the best choice is E.