Gene transcription is a fundamental cellular process carried out by RNA polymerase
(RNAP). Transcription initiation is highly regulated, and in bacteria, transcription initiation is …

The transcriptional regulator Spo0A activates transcription from two types of promoters. One
type of promoter is used by RNA polymerase containing τA, whereas the other type is used …

Gram-negative bacteria are formidable pathogens because their cell envelope presents an
adaptable barrier to environmental and host-mediated challenges. The stress response …

The sigma subunit of procaryotic RNA polymerases is responsible for specific promoter
recognition and transcription initiation. In addition to the major sigma factor, σ70, in …

The initiation of transcription is a complex process involving many different steps. These
steps are all potential control points for regulating gene expression, and many have been …

Alternative sigma factors provide a means of regulating gene expression in response to
various extracellular changes. One such class of sigma factors appears to control a variety of …

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 …

Group IV (extracytoplasmic function) sigma factors direct the expression of a large number of
regulons in bacteria. The activities of many Group IV sigma factors are inhibited by members …

Escherichia coli σ54 was analyzed by making a series of 16 internal deletions within its
gene and analyzing the properties of the mutant proteins. All of the mutant proteins except …

Pseudomonas bacteria are widespread and are found in soil and water, as well as
pathogens of both plants and animals. The ability of Pseudomonas to colonize many …