The molecular basis of selective promoter activation by the σ^S subunit of RNA polymerase

Abstract

. However, when s S is ectopically expressed in exponential phase, it shows only basal activity (Kvint et al., 2000). Here, we try to highlight how Es S manages to activate its regulon in vivo only in physiologically appropriate conditions. In general, Es S efficiency depends on the cellular s S concentration (controlled at the levels of transcription, translation and proteolysis) and Es S holoenzyme formation and activity, whereas Es S promoter specificity is achieved by a combination of cis-and trans-acting promoter features. Intrinsic promoter features support distinct promoter utilization by Es S and Es 70

Small RNA-based feedforward loop with AND-gate logic regulates extrachromosomal DNA transfer in Salmonella

“…4A). Intriguingly, the associated promoter contains a highly conserved cytosine at position −13, which is a hallmark of σ S -dependent promoters; this nucleotide contacts amino acid E458 in σ S and counterselects for binding of the housekeeping σ 70 (47). To test a potential σ S dependence of the ricI promoter, we inserted a lacZ reporter gene downstream of it in the Salmonella chromosome (48).…”

New insights into the regulatory networks of paralogous genes in bacteria

“…, may share overlapping sets of target genes (Typas et al, 2007). The presence of cis-acting elements located in the promoter region, as well as the activity of trans-acting proteins, establishes whether a promoter is recognized by RNA polymerase containing s According to our compiled data referring to the regulatory networks of paralogous genes, there are 100 out of 477 (21 %) groups in E. coli and 144 out of 483 (30 %) groups in B. subtilis that are regulated by alternative sigma, antisigma or anti-anti-sigma factors (Supplementary Tables S1 and S2).…”

Integration of Global Regulatory Mechanisms Controlling Vibrio Cholerae Behavior

“…It is not clear what makes a given promoter selective for transcription by RpoS. Several promoter elements have been described including an upstream (UP) element, a more degenerate -35 region, a cytosine at -13, and a AT-rich region downstream from -10 (Hengge-Aronis, 2002a; Typas et al, 2007). It also has been suggested that histone-like proteins such as H-NS, the Leucine-responsive protein (Lrp), or the integration host factor (IHF) can contribute to  S promoter selectivity (HenggeAronis, 2002a;Hengge-Aronis, 1999;Typas et al, 2007).…”

“…Several promoter elements have been described including an upstream (UP) element, a more degenerate -35 region, a cytosine at -13, and a AT-rich region downstream from -10 (Hengge-Aronis, 2002a; Typas et al, 2007). It also has been suggested that histone-like proteins such as H-NS, the Leucine-responsive protein (Lrp), or the integration host factor (IHF) can contribute to  S promoter selectivity (HenggeAronis, 2002a;Hengge-Aronis, 1999;Typas et al, 2007). For instance, many  S -dependent genes are repressed by H-NS, and association of RNAP with  S on these promoters may overcome H-NS transcriptional repression (Barth et al, 1995;Bouvier et al, 1998;HenggeAronis, 1999).…”