Bacterial sigma (σ) factor, along with RNA polymerase core enzyme, initiates gene transcription from specific promoter regions and therefore regulates clusters of genes in response to a particular situation. The extracytoplasmic function (ECF) σ factors are a class of alternative σ factors that are often associated with environmental signal transduction across the bacterial membrane, in which external signal triggers the release of active σ from the membrane-anchored anti-σ factor. Gram-positive model organism Bacillus subtilis (B. subtilis) has seven ECF σ factors: σ^M, σ^V, σ^X, σ^W, σ^Y, σ^Z and σ^YlaC. Although all these ECF σ factors were found to be involved in B. subtilis antibiotic resistance, σ^W is among the most studied and considered to play a pivotal role in responding to antimicrobial stresses. σ^W is under tight control and remains deactivated until exposure to external stimuli, after which proteases PrsW and RasP cleave the specific anti-sigma factor—RsiW to release and activate σ^W. Membrane anchored protein YsdB is a negative regulator of this activation, possibly via its direct interaction with PrsW and/or RsiW. Importantly, YsdB is well conserved among Bacilli, including pathogenic bacteria like Bacillus cereus. In this study, we describe the chemical shift assignments of the cytoplasmic domain of YsdB (29-130) of B. subtilis in solution as a basis for further interaction studies and structure determination. The near-complete assignment and the solution structure that will follow could provide a further understanding in σ^W regulation.

细菌西格玛 (σ) 因子与 RNA 聚合酶核心酶一起从特定启动子区域启动基因转录，从而调节基因簇以响应特定情况。胞质外功能（ECF）σ因子是一类替代σ因子，通常与跨细菌膜的环境信号转导相关，其中外部信号触发膜锚定的抗σ因子释放活性σ。革兰氏阳性模式生物枯草芽孢杆菌( B. subtilis ) 具有七个 ECF σ 因子：σ ^M 、σ ^V 、σ ^X 、σ ^W 、σ ^Y 、σ ^Z和 σ ^YlaC 。尽管所有这些 ECF σ 因子都被发现与枯草芽孢杆菌抗生素耐药性有关，但 σ ^W是研究最多的因子之一，并被认为在应对抗菌应激方面发挥着关键作用。 σ ^W受到严格控制并保持失活状态，直到暴露于外部刺激，之后蛋白酶 PrsW 和 RasP 裂解特定的抗 Sigma 因子 RsiW 以释放并激活 σ ^W 。膜锚定蛋白 YsdB 是这种激活的负调节因子，可能是通过其与 PrsW 和/或 RsiW 的直接相互作用实现的。重要的是，YsdB 在芽孢杆菌中非常保守，包括蜡状芽孢杆菌等病原菌。在本研究中，我们描述了溶液中枯草芽孢杆菌YsdB (29-130) 细胞质结构域的化学位移分配，作为进一步相互作用研究和结构测定的基础。 接近完成的作业和随后的解决方案结构可以提供对 σ ^W调节的进一步理解。