Patz Sascha, Becker Yvonne, Richert-Pöggeler Katja R, Berger Beatrice, Ruppel Silke, Huson Daniel H, Becker Matthias
Algorithms in Bioinformatics, Center for Bioinformatics, University of Tübingen, 72074 Tübingen, Germany.
Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institute - Federal Research Centre for Cultivated Plants, 38104 Braunschweig, Germany.
J Adv Res. 2019 Apr 23;19:75-84. doi: 10.1016/j.jare.2019.04.003. eCollection 2019 Sep.
Type VI secretion systems and tailocins, two bacterial phage tail-like particles, have been reported to foster interbacterial competition. Both nanostructures enable their producer to kill other bacteria competing for the same ecological niche. Previously, type VI secretion systems and particularly R-type tailocins were considered highly specific, attacking a rather small range of competitors. Their specificity is conferred by cell surface receptors of the target bacterium and receptor-binding proteins on tailocin tail fibers and tail fiber-like appendages of T6SS. Since many R-type tailocin gene clusters contain only one tail fiber gene it was appropriate to expect small R-type tailocin target ranges. However, recently up to three tail fiber genes and broader target ranges have been reported for one plant-associated strain. Here, we show that having three tail fiber genes per R-type tailocin gene cluster is a common feature of several strains of Gram-negative (often plant-associated) bacteria of the genus . Knowledge about the specificity of type VI secretion systems binding to target bacteria is even lower than in R-type tailocins. Although the mode of operation implicated specific binding, it was only published recently that type VI secretion systems develop tail fiber-like appendages. Here again , exhibiting up to three different type VI secretion systems, may provide valuable insights into the antagonistic potential of plant-associated bacteria. Current understanding of the diversity and potential of phage tail-like particles is fragmentary due to various synonyms and misleading terminology. Consistency in technical terms is a precondition for concerted and purposeful research, which precedes a comprehensive understanding of the specific interaction between bacteria producing phage tail-like particles and their targets. This knowledge is fundamental for selecting and applying tailored, and possibly engineered, producer bacteria for antagonizing plant pathogenic microorganisms.
VI型分泌系统和尾丝菌素是两种细菌噬菌体样颗粒，据报道它们能促进细菌间的竞争。这两种纳米结构都能使产生它们的细菌杀死争夺相同生态位的其他细菌。以前，VI型分泌系统，特别是R型尾丝菌素被认为具有高度特异性，攻击范围相当小的竞争者。它们的特异性由靶细菌的细胞表面受体以及尾丝菌素尾纤维和T6SS尾纤维样附属物上的受体结合蛋白赋予。由于许多R型尾丝菌素基因簇只包含一个尾纤维基因，因此预计R型尾丝菌素的靶标范围较小是合理的。然而，最近报道了一种植物相关菌株的R型尾丝菌素有多达三个尾纤维基因且靶标范围更广。在这里，我们表明每个R型尾丝菌素基因簇有三个尾纤维基因是几种革兰氏阴性（通常与植物相关）细菌属菌株的共同特征。关于VI型分泌系统与靶细菌结合的特异性的了解甚至比R型尾丝菌素还要少。尽管其作用方式涉及特异性结合，但直到最近才报道VI型分泌系统会形成尾纤维样附属物。同样，这里展示的多达三种不同的VI型分泌系统，可能会为植物相关细菌的拮抗潜力提供有价值的见解。由于各种同义词和误导性术语，目前对噬菌体样颗粒的多样性和潜力的理解是零碎的。技术术语的一致性是进行协调和有目的研究的前提条件，而这是全面理解产生噬菌体样颗粒的细菌与其靶标之间特定相互作用的先决条件。这些知识对于选择和应用定制的、可能经过工程改造的产生细菌来对抗植物病原微生物至关重要。
