It is clear that multiple sites of interaction exist between sigmas and core subunits, likely
reflecting the changing pattern of interactions that occur sequentially during the complex …

The σS and σ70 subunits of Escherichia coli RNA polymerase recognize very similar
promoter sequences. Therefore, many promoters can be activated by both holoenzymes in …

The first approach to defining the interaction of these proteins examined core binding of
various deletion derivatives of sigma. Scott Lesley and Richard Burgess identified region 2.1 …

The control of bacterial transcription initiation depends on a primary σ factor for
housekeeping functions, as well as alternative σ factors that control regulons in response to …

Extracytoplasmic function (ECF) sigma factors are a heterogeneous group of alternative
sigma factors that regulate gene expression in response to a variety of conditions, including …

Sigma factors provide promoter recognition specificity to RNA polymerase holoenzyme,
contribute to DNA strand separation, and then dissociate from the core enzyme following …

840 HELMANN & CHAMBERLIN alternative a factors (3, 9-12). Hence, these a factors play a
determining role in the specificity of transcription initiation. The genes encoding many a …

The Bacillus spo0H gene codes for sigma H, which, as part of the RNA polymerase
holoenzyme E sigma H, is responsible for the transcription of several genes which are …

Bacillus subtilis sigma-B is an alternate sigma factor implicated in controlling stationary-
phase gene expression. We characterized the genetic organization and regulation of the …

Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play
critical roles in transcription initiation, including the recognition and opening of promoters as …