Selective repression by Fis and H‐NS at the Escherichia coli dps promoter

Abstract

SummaryDps is a nucleoid-associated protein that plays a major role in condensation of the Escherichia coli chromosome in stationary phase. Here we show that two other nucleoid-associated proteins, Fis and H-NS, can bind at the dps gene promoter and downregulate its activity. Both Fis and H-NS selectively repress the dps promoter, preventing transcription initiation by RNA polymerase containing s 70 , the housekeeping s factor, but not by RNA polymerase containing s 38 , the stationary-phase s factor. Fis represses by trapping RNA polymerase containing s 70 at the promoter. In contrast, H-NS functions by displacing RNA polymerase containing s 70 , but not RNA polymerase containing s 38 . Dps levels are known to be very low in exponentially growing cells and rise sharply as cells enter stationary phase. Conversely, Fis levels are high in growing cells but fall to nearly zero in stationary-phase cells. Our data suggest a simple model to explain how the Dps-dependent supercompaction of the folded chromosome is triggered as cell growth ceases.

Roles of Nucleoid-Associated Proteins in Stress-Induced Mutagenic Break Repair in Starving Escherichia coli

“…H-NS is also a global regulator controlling the transcription of a few hundred genes, including those required for protection from osmotic and acid stresses (Barth et al 1995;Bouvier et al 1998;Chib and Mahadevan 2012). In growing cells, Fis and H-NS work together to repress the transcription of dps (Grainger et al 2008). Fis also represses cbpA transcription (Chintakayala et al 2013).…”

Gene order and chromosome dynamics coordinate spatiotemporal gene expression during the bacterial growth cycle

“…Thus, factor for inversion stimulation (FIS), a NAP abundant during the early exponential phase (18), regulates expression not only of the superhelicity determinants DNA gyrase subunits A and B (gyrA and gyrB) and topoisomerase I (topA) (19)(20)(21) but also other NAP-encoding genes including hns, α subunit of histone-like protein from E. coli strain U93 (hupA), and DNA binding protein from starved cells (dps) (22)(23)(24) and components of the transcription machinery such as σ 38 subunit of RNA polymerase rpoS (25). Similarly mutations affecting the selectivity of RNAP influence NAP production (26)(27)(28).…”

Mechanisms Regulating Escherichia Coli dps Gene Expression under Stress: Reconstruction on Kinetic Data

“…В то же время, из литературных данных известно, что в экспоненциальной фазе роста экспрессия гена dps E. coli негативно регулируется ТФ Fis и H-NS [10]. Имеют ли эти ТФ отношение к защите клеток от токсического воздействия кадмия?…”

“…Однако спектр агентов, активирующих экспрессию гена dps значительно шире [4,5], и механизмы реализации этих ответов неизвестны. Негативная роль ТФ Fis, H-NS и MntR в регуляции экспрессии гена dps E. coli не связывается авторами с реализацией какого-либо стрессового ответа [10,11].…”