Random sequences rapidly evolve into de novo promoters

Avihu H. Yona*, Eric J. Alm, Jeff Gore

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

76 Scopus citations


How new functions arise de novo is a fundamental question in evolution. We studied de novo evolution of promoters in Escherichia coli by replacing the lac promoter with various random sequences of the same size (∼100 bp) and evolving the cells in the presence of lactose. We find that ∼60% of random sequences can evolve expression comparable to the wild-type with only one mutation, and that ∼10% of random sequences can serve as active promoters even without evolution. Such a short mutational distance between random sequences and active promoters may improve the evolvability, yet may also lead to accidental promoters inside genes that interfere with normal expression. Indeed, our bioinformatic analyses indicate that E. coli was under selection to reduce accidental promoters inside genes by avoiding promoter-like sequences. We suggest that a low threshold for functionality balanced by selection against undesired targets can increase the evolvability by making new beneficial features more accessible.

Original languageAmerican English
Article number1530
JournalNature Communications
Issue number1
StatePublished - 1 Dec 2018
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2018 The Author(s).


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