Centre of Microbial and Plant Genetics, University of Leuven, Heverlee, Belgium.
FEMS Microbiol Rev. 2014 Jul;38(4):523-68. doi: 10.1111/1574-6976.12079. Epub 2014 Jul 3.
Members of the Pseudomonas genus produce diverse secondary metabolites affecting other bacteria, fungi or predating nematodes and protozoa but are also equipped with the capacity to secrete different types of ribosomally encoded toxic peptides and proteins, ranging from small microcins to large tailocins. Studies with the human pathogen Pseudomonas aeruginosa have revealed that effector proteins of type VI secretion systems are part of the antibacterial armamentarium deployed by pseudomonads. A novel class of antibacterial proteins with structural similarity to plant lectins was discovered by studying antagonism among plant-associated Pseudomonas strains. A genomic perspective on pseudomonad bacteriocinogeny shows that the modular architecture of S pyocins of P. aeruginosa is retained in a large diversified group of bacteriocins, most of which target DNA or RNA. Similar modularity is present in as yet poorly characterized Rhs (recombination hot spot) proteins and CDI (contact-dependent inhibition) proteins. Well-delimited domains for receptor recognition or cytotoxicity enable the design of chimeric toxins with novel functionalities, which has been applied successfully for S and R pyocins. Little is known regarding how these antibacterials are released and ultimately reach their targets. Other remaining issues concern the identification of environmental triggers activating these systems and assessment of their ecological impact in niches populated by pseudomonads.
假单胞菌属的成员产生多种影响其他细菌、真菌或捕食线虫和原生动物的次级代谢物，但也有能力分泌不同类型的核糖体编码的毒性肽和蛋白质，从小的微菌素到大的尾菌素。对人类病原体铜绿假单胞菌的研究表明，VI 型分泌系统的效应蛋白是假单胞菌抗菌武器库的一部分。通过研究与植物相关的假单胞菌菌株之间的拮抗作用，发现了一类具有与植物凝集素结构相似的新型抗菌蛋白。从假单胞菌细菌素生成的基因组角度来看，铜绿假单胞菌 S 噬菌体的模块化结构保留在一大组多样化的细菌素中，其中大多数针对 DNA 或 RNA。Rhs（重组热点）蛋白和 CDI（接触依赖性抑制）蛋白也存在类似的模块化。受体识别或细胞毒性的明确界定域可实现具有新型功能的嵌合毒素的设计，这已成功应用于 S 和 R 噬菌体。关于这些抗菌剂是如何释放的，以及它们最终如何到达目标，人们知之甚少。其他遗留问题涉及识别激活这些系统的环境触发因素，并评估它们在假单胞菌栖息的小生境中的生态影响。
