Peltier Johann, Hamiot Audrey, Garneau Julian R, Boudry Pierre, Maikova Anna, Hajnsdorf Eliane, Fortier Louis-Charles, Dupuy Bruno, Soutourina Olga
Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France.
Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
Commun Biol. 2020 Nov 27;3(1):718. doi: 10.1038/s42003-020-01448-5.
Toxin-antitoxin (TA) systems are widespread on mobile genetic elements and in bacterial chromosomes. In type I TA, synthesis of the toxin protein is prevented by the transcription of an antitoxin RNA. The first type I TA were recently identified in the human enteropathogen Clostridioides difficile. Here we report the characterization of five additional type I TA within phiCD630-1 (CD0977.1-RCd11, CD0904.1-RCd13 and CD0956.3-RCd14) and phiCD630-2 (CD2889-RCd12 and CD2907.2-RCd15) prophages of C. difficile strain 630. Toxin genes encode 34 to 47 amino acid peptides and their ectopic expression in C. difficile induces growth arrest that is neutralized by antitoxin RNA co-expression. We show that type I TA located within the phiCD630-1 prophage contribute to its stability and heritability. We have made use of a type I TA toxin gene to generate an efficient mutagenesis tool for this bacterium that allowed investigation of the role of these widespread TA in prophage maintenance.
毒素-抗毒素（TA）系统广泛存在于可移动遗传元件和细菌染色体中。在I型TA中，抗毒素RNA的转录可阻止毒素蛋白的合成。首个I型TA最近在人类肠道病原体艰难梭菌中被鉴定出来。在此，我们报告了艰难梭菌630菌株的phiCD630-1（CD0977.1-RCd11、CD0904.1-RCd13和CD0956.3-RCd14）和phiCD630-2（CD2889-RCd12和CD2907.2-RCd15）原噬菌体中另外5个I型TA的特征。毒素基因编码34至47个氨基酸的肽段，它们在艰难梭菌中的异位表达会诱导生长停滞，而抗毒素RNA的共表达可中和这种停滞。我们表明，位于phiCD630-1原噬菌体中的I型TA有助于其稳定性和遗传性。我们利用I型TA毒素基因开发了一种针对该细菌的高效诱变工具，可用于研究这些广泛存在的TA在原噬菌体维持中的作用。
