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Signal sensing by σ 54 ‐dependent regulators: derepression as a control mechanism
Author(s) -
Shingler Victoria
Publication year - 1996
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1996.388920.x
Subject(s) - effector , derepression , biology , sigma factor , transcription factor , microbiology and biotechnology , transcription (linguistics) , sigma , regulation of gene expression , transcriptional regulation , genetics , gene expression , mechanism (biology) , gene , rna polymerase , rna , psychological repression , linguistics , philosophy , epistemology , physics , quantum mechanics
Transcription by RNA polymerase utilizing the alternative sigma factor σ 54 is regulated by a distinct class of positive activators designated the σ 54 ‐dependent family. The activities of these regulators are themselves modulated in response to a wide variety of environmental signals. Factors that modulate the expression or the activity of the regulatory protein in response to chemical and metabolic changes are ultimately responsible for determining the level of expression of σ 54 ‐dependent genes and hence the diverse bacterial functions that they encode. Many members of the σ 54 ‐dependent family are part of two‐component sensor‐response systems. This MicroReview emphasizes recent data concerning the activities of a distinct subgroup of the σ 54 ‐dependent regulators that directly sense and respond with transcriptional activation to the presence of small effector molecules in their environment. The functional consequences of effector activation in terms of regulation of the enzymatic (ATPase) activity of these transcriptional activators and interdomain interactions are discussed.