赖氨酸和精氨酸甲基化是真核生物中酶活性和转录的重要调控因子。然而,对细菌中的这种共价修饰知之甚少。在这项工作中,我们研究了甲基化在细菌中的作用.通过重新分析来自代表六个门的48个细菌菌株的大型系统蛋白质组学数据集,我们发现,几乎四分之一的细菌蛋白质组被甲基化。许多这些甲基化蛋白在不同的细菌谱系中都是保守的,包括那些参与中心碳代谢和翻译的。具有最保守的甲基化位点的蛋白质是核糖体蛋白L11(bL11)。BL11甲基化五十年来一直是个谜,因为缺失其甲基转移酶PrmA不会导致细胞生长缺陷。比较蛋白质组学分析与大肠杆菌中ΔprmA突变体的无机多磷酸盐和鸟苷四/五磷酸盐测定相结合,表明bL11甲基化对于严格的反应信号传导很重要。在固定阶段,我们发现ΔprmA突变体损害了鸟苷四/五磷酸盐的产生。这导致无机多磷酸盐含量的降低,RNA和核糖体蛋白的积累,和异常的多重体轮廓。总的来说,我们的研究表明,进化上保守的bL11甲基化对于严格的反应信号和核糖体活性调节和周转是重要的。
目的:60多年前首次发现细菌中的蛋白质甲基化。从那以后,它的功能作用已被确定为只有少数蛋白质。为了更好地理解甲基化在细菌中的功能作用,我们分析了包含48种不同细菌的大型系统蛋白质组学数据集.我们的分析表明,核糖体蛋白通常在保守的残基处被甲基化,表明这些位点的甲基化可能在翻译中具有功能性作用。进一步的分析表明,核糖体蛋白L11的甲基化对于严格的反应信号和核糖体稳态很重要。
Lysine and arginine methylation is an important regulator of enzyme activity and transcription in eukaryotes. However, little is known about this covalent modification in bacteria. In this work, we investigated the role of methylation in bacteria. By reanalyzing a large phyloproteomics data set from 48 bacterial strains representing six phyla, we found that almost a quarter of the bacterial proteome is methylated. Many of these methylated proteins are conserved across diverse bacterial lineages, including those involved in central carbon metabolism and translation. Among the proteins with the most conserved methylation sites is ribosomal protein L11 (bL11). bL11 methylation has been a mystery for five decades, as the deletion of its methyltransferase PrmA causes no cell growth defects. Comparative proteomics analysis combined with inorganic polyphosphate and guanosine tetra/pentaphosphate assays of the ΔprmA mutant in Escherichia coli revealed that bL11 methylation is important for stringent response signaling. In the stationary phase, we found that the ΔprmA mutant has impaired guanosine tetra/pentaphosphate production. This leads to a reduction in inorganic polyphosphate levels, accumulation of RNA and ribosomal proteins, and an abnormal polysome profile. Overall, our investigation demonstrates that the evolutionarily conserved bL11 methylation is important for stringent response signaling and ribosomal activity regulation and turnover.
OBJECTIVE: Protein methylation in bacteria was first identified over 60 years ago. Since then, its functional role has been identified for only a few proteins. To better understand the functional role of methylation in bacteria, we analyzed a large phyloproteomics data set encompassing 48 diverse bacteria. Our analysis revealed that ribosomal proteins are often methylated at conserved residues, suggesting that methylation of these sites may have a functional role in translation. Further analysis revealed that methylation of ribosomal protein L11 is important for stringent response signaling and ribosomal homeostasis.