蛋白质乙酰化可以迅速改变细菌的生理,以响应环境或营养条件的变化,但是根瘤菌中关于这些修饰的信息很少。在这项研究中,我们报告了氮根瘤菌culinodans菌株ORS571的赖氨酸乙酰组,这是一种从热带豆科植物Sesbaniarostrata的茎结核中分离出的模型根瘤菌,能够在自由生活状态和共生过程中固定氮。使用抗体富集和液相色谱-串联质谱(LC-MS/MS)分析来表征乙酰基组。有2302个乙酰化位点来自982个蛋白质,占总蛋白质的20.8%。乙酰化基序的分析显示了乙酰化赖氨酸周围的氨基酸残基的偏好。先前表征为参与菌株ORS571的趋化性的反应调节剂CheY1被鉴定为乙酰化蛋白,CheY1乙酰化位点的突变显著损害了菌株的运动性。此外,对Zn+依赖性脱乙酰酶(AZC_0414)进行了表征,缺失突变株的构建表明它在趋化性中起作用。我们的研究提供了ORS571中赖氨酸乙酰化的第一个全球分析,表明乙酰化在各种生理过程中起作用。此外,我们证明了它参与趋化过程。ORS571的乙酰基组提供了研究根瘤菌生理调节机制的见解。重要性乙酰化是调节蛋白质功能的重要修饰,已发现可调节各种细菌的生理过程。根瘤菌ORS571的生理学在自由生活和与宿主共生时受到多种机制的调节;然而,乙酰化的调节作用尚不清楚。这里,我们采用全乙酰化组的方法来鉴定A.caulinodansORS571中的乙酰化蛋白,并进行聚类分析.初步研究了趋化蛋白的乙酰化,并对参与趋化性的上游乙酰化调节酶进行了表征。这些发现为探索根瘤菌的生理机制提供了新的见解。
Protein acetylation can quickly modify the physiology of bacteria to respond to changes in environmental or nutritional conditions, but little information on these modifications is available in rhizobia. In this study, we report the lysine
acetylome of Azorhizobium caulinodans strain ORS571, a model rhizobium isolated from stem nodules of the tropical legume Sesbania rostrata that is capable of fixing nitrogen in the free-living state and during symbiosis. Antibody enrichment and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis were used to characterize the
acetylome. There are 2,302 acetylation sites from 982 proteins, accounting for 20.8% of the total proteins. Analysis of the acetylated motifs showed the preferences for the amino acid residues around acetylated lysines. The response regulator CheY1, previously characterized to be involved in chemotaxis in strain ORS571, was identified as an acetylated protein, and a mutation of the acetylated site of CheY1 significantly impaired the strain\'s motility. In addition, a Zn+-dependent deacetylase (AZC_0414) was characterized, and the construction of a deletion mutant strain showed that it played a role in chemotaxis. Our study provides the first global analysis of lysine acetylation in ORS571, suggesting that acetylation plays a role in various physiological processes. In addition, we demonstrate its involvement in the chemotaxis process. The
acetylome of ORS571 provides insights to investigate the regulation mechanism of rhizobial physiology. IMPORTANCE Acetylation is an important modification that regulates protein function and has been found to regulate physiological processes in various bacteria. The physiology of rhizobium A. caulinodans ORS571 is regulated by multiple mechanisms both when free living and in symbiosis with the host; however, the regulatory role of acetylation is not yet known. Here, we took an
acetylome-wide approach to identify acetylated proteins in A. caulinodans ORS571 and performed clustering analyses. Acetylation of chemotaxis proteins was preliminarily investigated, and the upstream acetylation-regulating enzyme involved in chemotaxis was characterized. These findings provide new insights to explore the physiological mechanisms of rhizobia.