Related Experiment Video
Updated: Sep 27, 2025

DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems
Published on: July 21, 2014
Mechanisms of Action of Non-Canonical ECF Sigma Factors
Francisco Javier Marcos-Torres1, Aurelio Moraleda-Muñoz2, Francisco Javier Contreras-Moreno2
1Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, 18011 Granada, Spain.
Abstract:
Extracytoplasmic function (ECF) sigma factors are subunits of the RNA polymerase specialized in activating the transcription of a subset of genes responding to a specific environmental condition. The signal-transduction pathways where they participate can be activated by diverse mechanisms. The most common mechanism involves the action of a membrane-bound anti-sigma factor, which sequesters the ECF sigma factor, and releases it after the stimulus is sensed. However, despite most of these systems following this canonical regulation, there are many ECF sigma factors exhibiting a non-canonical regulatory mechanism. In this review, we aim to provide an updated and comprehensive view of the different activation mechanisms known for non-canonical ECF sigma factors, detailing their inclusion to the different phylogenetic groups and describing the mechanisms of regulation of some of their representative members such as EcfG from Rhodobacter sphaeroides, showing a partner-switch mechanism; EcfP from Vibrio parahaemolyticus, with a phosphorylation-dependent mechanism; or CorE from Myxococcus xanthus, regulated by a metal-sensing C-terminal extension.
More Related Videos
Related Concept Videos
Global Regulatory Systems
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
NF-κB-dependent Signaling Pathway
NF-κB-dependent Signaling Mechanism
The...
Stringent Response in E. coli
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
RNA Polymerase II Accessory Proteins

