摘要
小调节RNA在适应不断变化的条件中发挥重要作用。在这里，我们描述了差异表达的小调节RNA（sRNA），其影响植物病原体根癌农杆菌中的各种细胞过程使用生物信息学预测和比较蛋白质组学的组合，我们鉴定了9个靶标，其中大多数受sRNA的正调节。根据这些目标，我们将sRNA PmaR命名为肽聚糖生物合成，运动性和氨苄青霉素抗性调节剂。农杆菌属众所周知，天然对高氨苄青霉素浓度具有抗性，我们现在可以通过PmaR介导的β-内酰胺酶基因调控来解释这种表型。结构探测显示sRNA的勺状结构，单链在体内和体外参与靶相互作用的环几种核糖调节剂与抗生素抗性机制有关，例如摄取和外排转运蛋白，但PmaR代表直接控制抗生素抗性基因表达的sRNA的第一个例子。进展根癌农杆菌（Agrobacterium tumefaciens）能够感染各种真双歧杆菌，导致冠状肿瘤形成。基于其独特的基因转移能力，农杆菌作为植物细胞遗传操作的关键生物技术工具。在该生物体中存在数百种推定的sRNA表明核心调节对根癌农杆菌生理学的相当大的影响。在这里，我们描述了sRNA PmaR的生物学功能，其控制对生长，运动和毒力至关重要的各种过程。在PmaR直接靶向的基因中，编码β-内酰胺酶的ampC编码赋予氨苄青霉素抗性，这表明sRNA对于根际竞争微生物组成的适应性至关重要。

Small regulatory RNAs play an important role in the adaptation to changing conditions. Here, we describe a differentially expressed small regulatory RNA (sRNA) that affects various cellular processes in the plant pathogen Agrobacterium tumefaciens Using a combination of bioinformatic predictions and comparative proteomics, we identified nine targets, most of which are positively regulated by the sRNA. According to these targets, we named the sRNA PmaR for peptidoglycan biosynthesis, motility, and ampicillin resistance regulator. Agrobacterium spp. are long known to be naturally resistant to high ampicillin concentrations, and we can now explain this phenotype by the positive PmaR-mediated regulation of the beta-lactamase gene ampC Structure probing revealed a spoon-like structure of the sRNA, with a single-stranded loop that is engaged in target interaction in vivo and in vitro Several riboregulators have been implicated in antibiotic resistance mechanisms, such as uptake and efflux transporters, but PmaR represents the first example of an sRNA that directly controls the expression of an antibiotic resistance gene.IMPORTANCE The alphaproteobacterium Agrobacterium tumefaciens is able to infect various eudicots causing crown gall tumor formation. Based on its unique ability of interkingdom gene transfer, Agrobacterium serves as a crucial biotechnological tool for genetic manipulation of plant cells. The presence of hundreds of putative sRNAs in this organism suggests a considerable impact of riboregulation on A. tumefaciens physiology. Here, we characterized the biological function of the sRNA PmaR that controls various processes crucial for growth, motility, and virulence. Among the genes directly targeted by PmaR is ampC coding for a beta-lactamase that confers ampicillin resistance, suggesting that the sRNA is crucial for fitness in the competitive microbial composition of the rhizosphere.

https://www.ncbi.nlm.nih.gov/pubmed/30425148