Nucleotide composition affects codon usage toward the 3’-end

Fouad Zahdeh, Liran Carmel*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


The 3’-end of the coding sequence in several species is known to show specific codon usage bias. Several factors have been suggested to underlie this phenomenon, including selection against translation efficiency, selection for translation accuracy, and selection against RNA folding. All are supported by some evidence, but there is no general agreement as to which factors are the main determinants. Nor is it known how universal this phenomenon is, and whether the same factors explain it in different species. To answer these questions, we developed a measure that quantifies the codon usage bias at the gene end, and used it to compute this bias for 91 species that span the three domains of life. In addition, we characterized the codons in each species by features that allow discrimination between the different factors. Combining all these data, we were able to show that there is a universal trend to favor AT-rich codons toward the gene end. Moreover, we suggest that this trend is explained by avoidance from forming RNA secondary structures around the stop codon, which may interfere with normal translation termination.

Original languageAmerican English
Article numbere0225633
JournalPLoS ONE
Issue number12
StatePublished - 1 Dec 2019

Bibliographical note

Publisher Copyright:
© 2019 Zahdeh, Carmel. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Dive into the research topics of 'Nucleotide composition affects codon usage toward the 3’-end'. Together they form a unique fingerprint.

Cite this