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Where to begin? Sigma factors and the selectivity of transcription initiation in bacteria
Author(s) -
Helmann John D.
Publication year - 2019
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/mmi.14309
Subject(s) - biology , sigma factor , regulon , genetics , rna polymerase , computational biology , transcription (linguistics) , gene , rna , dna , gene expression , transcription factor , linguistics , philosophy
Summary Transcription is the fundamental process that enables the expression of genetic information. DNA‐directed RNA polymerase (RNAP) uses one strand of the DNA duplex as template to produce complementary RNA molecules that serve in translation (rRNA, tRNA), protein synthesis (mRNA) and regulation (sRNA). Although the RNAP core is catalytically competent for RNA synthesis, the selectivity of transcription initiation requires a sigma (σ) factor for promoter recognition and opening. Expression of alternative σ factors provides a powerful mechanism to control the expression of discrete sets of genes (a σ regulon) in response to specific nutritional, developmental or stress‐related signals. Here, I review the key insights that led to the original discovery of σ factor 50 years ago and the subsequent discovery of alternative σ factors as a ubiquitous mechanism of bacterial gene regulation. These studies form a prelude to the more recent, genomics‐enabled insights into the vast diversity of σ factors in bacteria.