PDF(Pubmed)
Abstract：
Pyoverdines are iron-chelating siderophores employed by various pseudomonads to promote their growth in iron-limited environments, facilitating both beneficial and detrimental interactions with co-inhabiting microbes or hosts, including plants and animals. The fluorescent pseudomonads produce fluorescent pyoverdines comprised of a conserved central chromophore and a unique strain-specific peptidic side chain produced by non-ribosomal peptide synthetases. Pyoverdine Pf5 (PVD-Pf5) is produced by Pseudomonas protegens Pf-5, a species known for supporting plant growth and its involvement in plant pathogen control. To develop a means of exploring the dynamics of P. protegens activity in soil and in the rhizosphere, we selected DNA aptamers that specifically recognize PVD-Pf5 with high affinities. Two selected aptamers with only 16% identity in sequence were examined for structure and function. We found evidence that both aptamers form structures in their apo-forms and one aptamer has structural features suggesting the presence of a G-quadruplex. Although their tertiary structures are predicted to be different, both aptamers bind the target PVD-Pf5 with similar affinities and do not bind other siderophores, including the related pyoverdine, pseudobactin, produced by Pseudomonas sp. B10. One aptamer binds the pyoverdine peptide component and may also interact with the chromophore. This aptamer was integrated into a nanoporous aluminum oxide biosensor and demonstrated to successfully detect PVD-Pf5 and not to detect other siderophores that do not bind to the aptamer when evaluated in solution. This sensor provides a future opportunity to track the locations of P. protegens around plant roots and to monitor PVD-Pf5 production and movement through the soil.
摘要：
Pyoverdines是各种假单胞菌使用的铁螯合铁载体，以促进其在铁有限的环境中的生长，促进与共同居住的微生物或宿主的有益和有害相互作用，包括植物和动物。荧光假单胞菌产生由保守的中心发色团和由非核糖体肽合成酶产生的独特的菌株特异性肽侧链组成的荧光pyoverdine。PyoverdinePf5（PVD-Pf5）由假单胞菌蛋白Pf-5产生，该物种以支持植物生长及其参与植物病原体控制而闻名。为了开发一种探索土壤和根际中P.蛋白质原活性动态的方法，我们选择了具有高亲和力的特异性识别PVD-Pf5的DNA适体。检查在序列中仅具有16%同一性的两个选择的适体的结构和功能。我们发现两种适体都以其apo形式形成结构，一种适体具有结构特征，表明存在G-四链体。尽管预测它们的三级结构不同，两种适体都以相似的亲和力结合目标PVD-Pf5，并且不结合其他铁载体，包括相关的pyoverdine,假细胞素,由假单胞菌产生。B10.一个适体结合焦菌苷肽组分,并且还可以与发色团相互作用。将该适体整合到纳米多孔氧化铝生物传感器中,并证明当在溶液中评估时,成功检测PVD-Pf5,而不检测不与适体结合的其他铁载体。该传感器提供了一个未来的机会来跟踪植物根部周围的P.protogins的位置，并监测PVD-Pf5的产生和通过土壤的移动。
