Huang X, Gaballa A, Cao M, Helmann J D
Section of Microbiology, Cornell University, Ithaca, NY 14853-8101, USA.
Mol Microbiol. 1999 Jan;31(1):361-71. doi: 10.1046/j.1365-2958.1999.01180.x.
The Bacillus subtilis sigW gene encodes an extracytoplasmic function (ECF) sigma factor that is expressed in early stationary phase from a sigW-dependent autoregulatory promoter, PW. Using a consensus-based search procedure, we have identified 15 operons preceded by promoters similar in sequence to PW. At least 14 of these promoters are dependent on sigma W both in vivo and in vitro as judged by lacZ reporter fusions, run-off transcription assays and nucleotide resolution start site mapping. We conclude that sigma W controls a regulon of more than 30 genes, many of which encode membrane proteins of unknown function. The sigma W regulon includes a penicillin binding protein (PBP4*) and a co-transcribed amino acid racemase (RacX), homologues of signal peptide peptidase (YteI), flotillin (YuaG), ABC transporters (YknXYZ), non-haem bromoperoxidase (YdjP), epoxide hydrolase (YfhM) and three small peptides with structural similarities to bacteriocin precursor polypeptides. We suggest that sigma W activates a large stationary-phase regulon that functions in detoxification, production of anti-microbial compounds or both.
枯草芽孢杆菌的sigW基因编码一种胞外功能（ECF）σ因子，该因子在稳定期早期从依赖sigW的自调控启动子PW表达。通过基于共有序列的搜索程序，我们鉴定出15个操纵子，其启动子序列与PW相似。通过lacZ报告基因融合、 runoff转录分析和核苷酸分辨率起始位点作图判断，这些启动子中至少有14个在体内和体外均依赖σW。我们得出结论，σW控制着一个由30多个基因组成的调控子，其中许多基因编码功能未知的膜蛋白。σW调控子包括一种青霉素结合蛋白（PBP4*）和一个共转录的氨基酸消旋酶（RacX）、信号肽肽酶（YteI）的同源物、浮膜蛋白（YuaG）、ABC转运蛋白（YknXYZ）、非血红素溴过氧化物酶（YdjP）、环氧化物水解酶（YfhM）以及三种与细菌素前体多肽结构相似的小肽。我们认为，σW激活了一个在解毒、抗菌化合物产生或两者中发挥作用的大型稳定期调控子。
