Stöver A G, Driks A
Department of Microbiology and Immunology, Loyola University Medical Center, Maywood, Illinois 60153, USA.
J Bacteriol. 1999 Sep;181(17):5476-81. doi: 10.1128/JB.181.17.5476-5481.1999.
Previously, we identified a novel component of Bacillus subtilis spores, called TasA, which possesses antibacterial activity. TasA is made early in spore formation, as cells enter stationary phase, and is secreted into the medium as well as deposited into the spore. Here, we show that tasA expression can occur as cells enter stationary phase even under sporulation-repressing conditions, indicating that TasA is a transition-phase protein. tasA and two upstream genes, yqxM and sipW, likely form an operon, transcription of which is under positive control by the transition-phase regulatory genes spo0A and spo0H and negative control by the transition phase regulatory gene abrB. These results are consistent with the suggestion that yqxM, sipW, and tasA constitute a transition phase operon that could play a protective role in a variety of cellular responses to stress during late-exponential-phase and early-stationary-phase growth in B. subtilis.
此前，我们鉴定出枯草芽孢杆菌孢子的一种新成分，称为TasA，它具有抗菌活性。TasA在孢子形成早期产生，即细胞进入稳定期时，它会分泌到培养基中并沉积到孢子中。在这里，我们表明，即使在抑制孢子形成的条件下，tasA的表达也能在细胞进入稳定期时发生，这表明TasA是一种过渡阶段蛋白。tasA与两个上游基因yqxM和sipW可能形成一个操纵子，其转录受过渡阶段调控基因spo0A和spo0H的正调控以及过渡阶段调控基因abrB的负调控。这些结果与以下观点一致，即yqxM、sipW和tasA构成一个过渡阶段操纵子，该操纵子可能在枯草芽孢杆菌指数后期和稳定期早期生长期间对各种应激的细胞反应中发挥保护作用。
