title: The anti-sigma factors.
abstract: A mechanism for regulating gene expression at the level of transcription utilizes an antagonist of the sigma transcription factor known as the anti-sigma (anti-sigma) factor. The cytoplasmic class of anti-sigma factors has been well characterized. The class includes AsiA form bacteriophage T4, which inhibits Escherichia coli sigma 70; FlgM, present in both gram-positive and gram-negative bacteria, which inhibits the flagella sigma factor sigma 28; SpoIIAB, which inhibits the sporulation-specific sigma factor, sigma F and sigma G, of Bacillus subtilis; RbsW of B. subtilis, which inhibits stress response sigma factor sigma B; and DnaK, a general regulator of the heat shock response, which in bacteria inhibits the heat shock sigma factor sigma 32. In addition to this class of well-characterized cytoplasmic anti-sigma factors, a new class of homologous, inner-membrane-bound anti-sigma factors has recently been discovered in a variety of eubacteria. This new class of anti-sigma factors regulates the expression of so-called extracytoplasmic functions, and hence is known as the ECF subfamily of anti-sigma factors. The range of cell processes regulated by anti-sigma factors is highly varied and includes bacteriophage phage growth, sporulation, stress response, flagellar biosynthesis, pigment production, ion transport, and virulence.
authors.affiliation: Department of Microbiology, University of Washington, Seattle 98195, USA. hughes@u.washington.edu
authors.forename: K T
authors.initials: KT
authors.lastname: Hughes
authors.forename: K
authors.initials: K
authors.lastname: Mathee
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000494:pharmacology; D001426:Bacterial Proteins / Q000494:pharmacology / Q000502:physiology; D017122:Bacteriophage T4 / Q000737:chemistry; D002352:Carrier Proteins / Q000494:pharmacology / Q000502:physiology; D004268:DNA-Binding Proteins / Q000494:pharmacology; D004926:Escherichia coli / Q000737:chemistry; D029968:Escherichia coli Proteins; D005407:Flagella / Q000737:chemistry; D018840:HSP70 Heat-Shock Proteins / Q000494:pharmacology / Q000502:physiology; D008565:Membrane Proteins / Q000494:pharmacology; D026901:Membrane Transport Proteins; D016941:Myxococcus xanthus / Q000737:chemistry; D010776:Photobacterium / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000472:pathogenicity; D012475:Salmonella / Q000472:pathogenicity; D012808:Sigma Factor / Q000037:antagonists & inhibitors* / Q000494:pharmacology / Q000502:physiology; D013171:Spores, Bacterial / Q000737:chemistry; D014157:Transcription Factors / Q000494:pharmacology / Q000502:physiology; D014764:Viral Proteins / Q000494:pharmacology / Q000502:physiology; D014774:Virulence
chemical_list: C079619:AlgU protein, Pseudomonas aeruginosa; C078876:AsiA protein, Enterobacteria phage T4; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C091096:CarR protein, Azospirillum brasilense; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C490539:FecI protein, E coli; C093541:FecR protein, E coli; C064971:FliA protein, Bacteria; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C063757:MucA protein, Bacteria; C088234:PupI protein, Pseudomonas putida; C088235:PupR protein, Pseudomonas putida; C080358:RsbW protein, bacteria; D012808:Sigma Factor; D014157:Transcription Factors; D014764:Viral Proteins; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; C063202:sporulation-specific sigma factors; C071266:FlgM protein, Bacteria; C063842:dnaK protein, E coli