Public Health Research Institute, Rutgers University , Newark, New Jersey, USA.
Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University , Newark, New Jersey, USA.
mBio. 2023 Aug 31;14(4):e0126923. doi: 10.1128/mbio.01269-23. Epub 2023 Aug 9.
In , the RicT (YaaT), RicA (YmcA), and RicF (YlbF) proteins, which form a stable ternary complex, are needed together with RNase Y (Rny) to cleave and thereby stabilize several key transcripts encoding enzymes of intermediary metabolism. We show here that RicT, but not RicA or RicF, forms a stable complex with Rny and that this association requires the presence of RicA and RicF. We propose that RicT is handed off from the ternary complex to Rny. We show further that the two iron-sulfur clusters carried by the ternary Ric complex are required for the formation of the stable RicT-Rny complex. We demonstrate that proteins of the degradosome-like network of , which also interact with Rny, are dispensable for processing of the operon. Thus, Rny participates in distinct RNA-related processes, determined by its binding partners, and a RicT-Rny complex is likely the functional entity for mRNA maturation. IMPORTANCE The action of nucleases on RNA is universal and essential for all forms of life and includes processing steps that lead to the mature and functional forms of certain transcripts. In it has been shown that key transcripts for energy-producing steps of glycolysis, for nitrogen assimilation, and for oxidative phosphorylation, all of them crucial processes of intermediary metabolism, are cleaved at specific locations, resulting in mRNA stabilization. The proteins required for these cleavages in [Rny (RNase Y), RicA (YmcA), RicF (YlbF), and RicT (YaaT)] are broadly conserved among the firmicutes, including several important pathogens, hinting that regulatory mechanisms they control may also be conserved. Several aspects of these regulatory events have been explored: phenotypes associated with the absence of these proteins have been described, the impact of these absences on the transcriptome has been documented, and there has been significant exploration of the biochemistry and structural biology of Rny and the Ric proteins. The present study further advances our understanding of the association of Ric proteins and Rny and shows that a complex of Rny with RicT is probably the entity that carries out mRNA maturation.
在 中，RicT（YaaT）、RicA（YmcA）和 RicF（YlbF）蛋白形成稳定的三元复合物，与 RNase Y（Rny）一起需要切割并稳定几个关键的中间代谢酶编码的关键转录物。我们在这里表明 RicT 而不是 RicA 或 RicF 与 Rny 形成稳定的复合物，并且这种关联需要 RicA 和 RicF 的存在。我们提出 RicT 从三元复合物递交给 Rny。我们进一步表明，三元 Ric 复合物携带的两个铁硫簇对于稳定的 RicT-Rny 复合物的形成是必需的。我们证明，与 Rny 相互作用的网络的 Degradosome 样蛋白对于 操纵子的加工是可有可无的。因此，Rny 参与了不同的 RNA 相关过程，这取决于其结合伙伴，并且 RicT-Rny 复合物可能是 mRNA 成熟的功能实体。重要性核酸内切酶对 RNA 的作用是普遍存在的，对于所有形式的生命都是必不可少的，包括导致某些转录物成熟和功能形式的加工步骤。在 中已经表明，糖酵解、氮同化和氧化磷酸化的关键转录物，所有这些都是中间代谢的关键过程，都在特定位置被切割，导致 mRNA 稳定。 [Rny（RNase Y）、RicA（YmcA）、RicF（YlbF）和 RicT（YaaT）] 所需的蛋白质在厚壁菌门中广泛保守，包括几个重要的病原体，这表明它们控制的调节机制也可能保守。这些调节事件的几个方面已经得到了探索：描述了缺乏这些蛋白质的表型，记录了这些缺失对转录组的影响，并且对 Rny 和 Ric 蛋白质的生物化学和结构生物学进行了大量探索。本研究进一步提高了我们对 Ric 蛋白和 Rny 之间的关联的理解，并表明 Rny 与 RicT 的复合物可能是执行 mRNA 成熟的实体。
