mRNA-programmed translation pauses in the targeting of E. coli membrane proteins.

In all living organisms, ribosomes translating membrane proteins are targeted to membrane translocons early in translation, by the ubiquitous signal recognition particle (SRP) system. In eukaryotes, the SRP Alu domain arrests translation elongation of membrane proteins until targeting is complete. Curiously, however, the Alu domain is lacking in most eubacteria.

A comprehensive tRNA deletion library unravels the genetic architecture of the tRNA pool.

Deciphering the architecture of the tRNA pool is a prime challenge in translation research, as tRNAs govern the efficiency and accuracy of the process. Towards this challenge, we created a systematic tRNA deletion library in Saccharomyces cerevisiae, aimed at dissecting the specific contribution of each tRNA gene to the tRNA pool and to the cell's fitness. By harnessing this resource, we observed that the majority of tRNA deletions show no appreciable phenotype in rich medium, yet under more challenging conditions, additional phenotypes were observed.

The role of codon selection in regulation of translation efficiency deduced from synthetic libraries.

Background: Translation efficiency is affected by a diversity of parameters, including secondary structure of the transcript and its codon usage. Here we examine the effects of codon usage on translation efficiency by re-analysis of previously constructed synthetic expression libraries in Escherichia coli.

Results: We define the region in a gene that takes the longest time to translate as the bottleneck.

An evolutionarily conserved mechanism for controlling the efficiency of protein translation.

Recent years have seen intensive progress in measuring protein translation. However, the contributions of coding sequences to the efficiency of the process remain unclear. Here, we identify a universally conserved profile of translation efficiency along mRNAs computed based on adaptation between coding sequences and the tRNA pool.