Global and local depletion of ternary complex limits translational elongation.
The translation of genetic information according to the sequence of the mRNA template occurs with high accuracy and fidelity. Critical events in each single step of translation are selection of transfer RNA (tRNA), codon reading and tRNA-regeneration for a new cycle. We developed a model that accurately describes the dynamics of single elongation steps, thus providing a systematic insight into the sensitivity of the mRNA translation rate to dynamic environmental conditions. Alterations in the concentration of the aminoacylated tRNA can transiently stall the ribosomes during translation which results, as suggested by the model, in two outcomes: either stress-induced change in the tRNA availability triggers the premature termination of the translation and ribosomal dissociation, or extensive demand for one tRNA species results in a competition between frameshift to an aberrant open-reading frame and ribosomal drop-off. Using the bacterial Escherichia coli system, we experimentally draw parallels between these two possible mechanisms.
Zhang
Gong
G
Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.
Fedyunin
Ivan
I
Miekley
Oskar
O
Valleriani
Angelo
A
Moura
Alessandro
A
Ignatova
Zoya
Z
D004926:Escherichia coli / Q000235:genetics; D008957:Models, Genetic; D010441:Peptide Chain Elongation, Translational; D010445:Peptide Elongation Factors / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D013269:Stochastic Processes
D010445:Peptide Elongation Factors; D012346:RNA, Transfer, Amino Acyl