Hughes K T, Mathee K
Department of Microbiology, University of Washington, Seattle 98195, USA.
Annu Rev Microbiol. 1998;52:231-86. doi: 10.1146/annurev.micro.52.1.231.
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.
一种在转录水平调节基因表达的机制利用了一种被称为抗西格玛（anti-sigma）因子的西格玛转录因子拮抗剂。胞质类抗西格玛因子已得到充分表征。该类别包括噬菌体T4的AsiA，它抑制大肠杆菌的西格玛70；存在于革兰氏阳性菌和革兰氏阴性菌中的FlgM，它抑制鞭毛西格玛因子西格玛28；枯草芽孢杆菌的SpoIIAB，它抑制枯草芽孢杆菌的孢子形成特异性西格玛因子西格玛F和西格玛G；枯草芽孢杆菌的RbsW，它抑制应激反应西格玛因子西格玛B；以及热休克反应的一般调节因子DnaK，它在细菌中抑制热休克西格玛因子西格玛32。除了这类已充分表征的胞质抗西格玛因子外，最近在多种真细菌中发现了一类新的同源的、内膜结合的抗西格玛因子。这类新的抗西格玛因子调节所谓的胞外功能的表达，因此被称为抗西格玛因子的ECF亚家族。抗西格玛因子调节的细胞过程范围非常广泛，包括噬菌体生长、孢子形成、应激反应、鞭毛生物合成、色素产生、离子运输和毒力。
