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Alternative sigma factors and the regulation of flagellar gene expression
Author(s) -
Helmann J. D.
Publication year - 1991
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 - 10.1111/j.1365-2958.1991.tb01847.x
Subject(s) - caulobacter crescentus , sigma factor , flagellum , biology , flagellin , chemotaxis , bacillus subtilis , microbiology and biotechnology , gene , transcription (linguistics) , transcription factor , genetics , promoter , bacteria , gene expression , receptor , bacterial protein , linguistics , philosophy
Summary Synthesis of bacterial flagella and the accompanying array of chemotaxis receptors and transducers represents a major commitment of energy and resources for a growing bacterial cell and is subject to numerous levels of regulation. Genes for flagellar and chemotaxis proteins are expressed in a complex transcriptional cascade. This regulatory hierarchy acts to ensure that the highly expressed filament structural protein, flagellin, is synthesized only after a prerequisite set of structural proteins has been expressed and properly assembled. Recent evidence suggests that many bacteria utilize an alternative sigma (σ) subunit, similar in specificity to the Bacillus subtilis σ 28 protein, to direct transcription of flagellin, chemotaxis and motility genes. In Caulobacter crescentus and Campylobacter spp., both a σ 54 ‐like factor and a σ 28 ‐like factor participate in the transcription of flagellar and chemotaxis genes. Conversely, a σ 28 ‐like factor controls non‐motility functions in at least one non‐flagellated organism.