Sequence-dependent model of genes with dual s factor preference

• Escherichia coli uses sigma factors to quickly control large gene cohorts during stress conditions. While most of its genes respond to a single sigma factor, approximately 5% of them have dual sigma factor preference. The most common are those responsive to both sigma(70), which controls housekeeping genes, and sigma(38), which activates genes during stationary growth and stresses. Using RNA-seq and flow-cytometry measurements, we show that 'sigma(70+38) genes' are nearly as upregulated in stationary growth as 'sigma(38) genes'. Moreover, we find a clear quantitative relationship between their promoter sequence and their response strength to changes in sigma(38) levels. We then propose and validate a sequence dependent model of sigma(70+38) genes, with dual sensitivity to sigma(38) and sigma(70), that is applicable in the exponential and stationary growth phases, as well in the transient period in between. We further propose a general model, applicable to other stresses and sigma factor combinations. Given this, promoters controlling sigma 70+38 genes (and variants) could become important building blocks of synthetic circuits with predictable, sequence-dependent sensitivity to transitions between the exponential and stationary growth phases.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

Dual s factor preference

Sequence-dependent gene expression model

RNA-seq

Flow cytometry

E. coli

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)