Balanced codon usage optimizes eukaryotic translational efficiency.

Autor: Wenfeng Qian, Jian-Rong Yang, Nathaniel M Pearson, Calum Maclean, Jianzhi Zhang
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: PLoS Genetics, Vol 8, Iss 3, p e1002603 (2012)
Druh dokumentu: article
ISSN: 1553-7390
1553-7404
DOI: 10.1371/journal.pgen.1002603
Popis: Cellular efficiency in protein translation is an important fitness determinant in rapidly growing organisms. It is widely believed that synonymous codons are translated with unequal speeds and that translational efficiency is maximized by the exclusive use of rapidly translated codons. Here we estimate the in vivo translational speeds of all sense codons from the budding yeast Saccharomyces cerevisiae. Surprisingly, preferentially used codons are not translated faster than unpreferred ones. We hypothesize that this phenomenon is a result of codon usage in proportion to cognate tRNA concentrations, the optimal strategy in enhancing translational efficiency under tRNA shortage. Our predicted codon-tRNA balance is indeed observed from all model eukaryotes examined, and its impact on translational efficiency is further validated experimentally. Our study reveals a previously unsuspected mechanism by which unequal codon usage increases translational efficiency, demonstrates widespread natural selection for translational efficiency, and offers new strategies to improve synthetic biology.
Databáze: Directory of Open Access Journals