PT  - JOURNAL ARTICLE
AU  - Lummy Maria Oliveira Monteiro
AU  - Letícia Magalhães Arruda
AU  - Rafael Silva-Rocha
TI  - Emergent properties in complex synthetic bacterial promoters
AID  - 10.1101/152934
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 152934
4099  - http://biorxiv.org/content/early/2017/06/20/152934.short
4100  - http://biorxiv.org/content/early/2017/06/20/152934.full
AB  - Regulation of gene expression in bacteria results from the interplay between transcriptional factors (TFs) at target promoters, and how the arrangement of binding sites determines the regulatory logic of promoters is not well known. Here, we generated and fully characterized a library of synthetic complex promoters for the global regulators, CRP and IHF, in Escherichia coli, formed by a weak -35/-10 consensus sequence preceded by four combinatorial binding sites for these TFs. We found that while cis-elements for CRP preferentially activate promoters when located immediately upstream of the promoter consensus, binding sites for IHF mainly function as “UP” elements and stimulate transcription in several different architectures in the absence of this protein. However, the combination of CRP- and IHF-binding sites resulted in emergent properties in these complex promoters, where the activity of combinatorial promoters cannot be predicted from the individual behavior of its components. Taken together, the results presented here add to the information on architecture-logic of complex promoters in bacteria.