Iriarte M, Stainier I, Cornelis G R
Microbial Pathogenesis Unit, Faculté de Médecine, Université Catholique de Louvain, Brussels, Belgium.
Infect Immun. 1995 May;63(5):1840-7. doi: 10.1128/iai.63.5.1840-1847.1995.
The chromosome of Yersinia enterocolitica encodes a heat-stable enterotoxin called Yst and a surface antigen called Myf, which closely resembles enterotoxin-associated fimbriae. Both factors could act in conjunction to produce diarrhea. Production of the enterotoxin is regulated by temperature, osmolarity, and pH and occurs only when bacteria reach the stationary phase. Myf production is regulated by temperature and pH and, as we show in this work, also occurs after the exponential growth phase. In an attempt to understand the late-phase expression of yst and myf, we cloned, sequenced, and mutagenized the gene encoding RpoS, an alternative sigma factor of the RNA polymerase involved in expression of stationary-phase genes in other enterobacteria. An intact rpoS gene was necessary for full expression of yst in the stationary phase but not for the expression of myf and of pYV-encoded virulence determinants.
小肠结肠炎耶尔森菌的染色体编码一种名为Yst的热稳定肠毒素和一种名为Myf的表面抗原，后者与肠毒素相关菌毛极为相似。这两种因子可能共同作用导致腹泻。肠毒素的产生受温度、渗透压和pH值调节，且仅在细菌进入稳定期时发生。Myf的产生受温度和pH值调节，正如我们在这项研究中所表明的，它也在指数生长期之后出现。为了理解yst和myf的晚期表达，我们克隆、测序并诱变了编码RpoS的基因，RpoS是RNA聚合酶的一种替代σ因子，参与其他肠道细菌中稳定期基因的表达。完整的rpoS基因对于yst在稳定期的充分表达是必需的，但对于myf和pYV编码的毒力决定簇的表达则不是必需的。
