tmRNA to the rescue : Structural motives for the salvage of stalled ribosomes

• During translation, mRNA molecules are incidentally damaged, leaving the ribosome unable to reach or recognize the stop codon and thus stalled with mRNA and a potentially harmful polypeptide product attached to tRNA in the ribosomal P-site. In bacteria, a process called trans-translation has evolved, where a protein-RNA complex (smpB-tmRNA) mimicks the role of aminoacyl charged tRNA in the ribosomal A-site. The ribosome then resumes protein synthesis guided by an mRNA-like portion of the tmRNA which ends with a stop codon and codes for a peptide sequence susceptible to proteolysis, thus allowing the bacteria to salvage stalled ribosomes and degrade ill-defined and potentially harmful protein products. In this article, we will recollect how structural studies have yielded a model for how the pre-translocation stages of trans-translation employing structural mimicry. We will also discuss possible models for

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology (hsv//eng)

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Keyword

trans-translation

tmRNA

SmpB

cryo electron microscopy

single particle

heterogeneity analysis

Bioengineering

Bioteknik

trans-translation

tmRNA

SmpB

cryo electron microscopy

single

particle

heterogeneity analysis

Publication and Content Type

vet (subject category)

art (subject category)