Journal of Molecular Evolution

, Volume 62, Issue 5, pp 536-550

First online:

Some Aspects of E. coli Promoter Evolution Observed in a Molecular Evolution Experiment

  • Shumo LiuAffiliated withNEC Laboratories AmericaDepartment of Physics, University of California at San Diego Email author 
  • , Albert LibchaberAffiliated withNEC Laboratories AmericaRockefeller University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


We devised a molecular evolution procedure to evolve E. coli promoter sequences and applied it to observe an arbitrary, nonfunctional sequence evolving into functional promoters. In the experiments, DNA sequence variations were generated with error-prone PCR and were inserted in the promoter region of the cat (chloramphenicol acetyl transferase) gene on a plasmid. Upon transforming the cells, functional promoters on the plasmid were selected according to the chloramphenicol resistance. Within a few cycles of mutation-selection, promoters emerged, and the sequences converged into a small number of groups. In the process, the extended minus 10 type of promoters emerged quickly, and small deletions were often involved in adjusting the length between the −35 and the −10 elements. Our results also suggest a possible selection for promoter stability against mutation.


Promoter Mutagenesis PCR Antibiotic selection Mutation frequency Extended minus 10