Identification of Three Type II Toxin-Antitoxin Systems in Model Bacterial Plant Pathogen <i>Dickeya dadantii</i> 3937

• Main Authors: Lidia Boss, Marcin Górniak, Alicja Lewańczyk, Joanna Morcinek-Orłowska, Sylwia Barańska, Agnieszka Szalewska-Pałasz
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: International Journal of Molecular Sciences
• Subjects: toxin-antitoxin; <i>ccdAB</i>; <i>ccdAB_2Dda</i>; phd-doc; <i>phd-doc_Dda</i>; dhiTA
• Online Access: https://www.mdpi.com/1422-0067/22/11/5932
• ISSN: 1661-6596; 1422-0067

Type II toxin-antitoxin (TA) systems are genetic elements usually encoding two proteins: a stable toxin and an antitoxin, which binds the toxin and neutralizes its toxic effect. The disturbance in the intracellular toxin and antitoxin ratio typically leads to inhibition of bacterial growth or bacterial cell death. Despite the fact that TA modules are widespread in bacteria and archaea, the biological role of these systems is ambiguous. Nevertheless, a number of studies suggests that the TA modules are engaged in such important processes as biofilm formation, stress response or virulence and maintenance of mobile genetic elements. The <i>Dickeya dadantii</i> 3937 strain serves as a model for pathogens causing the soft-rot disease in a wide range of angiosperm plants. Until now, several chromosome-encoded type II TA systems were identified in silico in the genome of this economically important bacterium<i>, </i>however so far only one of them was experimentally validated. In this study, we investigated three putative type II TA systems in <i>D. dadantii</i> 3937: <i>ccdAB_2Dda</i>, <i>phd-doc_Dda</i> and <i>dhiTA</i>, which represents a novel toxin/antitoxin superfamily. We provide an experimental proof for their functionality in vivo both in <i>D. dadantii</i> and <i>Escherichia coli</i>. Finally, we examined the prevalence of those systems across the Pectobacteriaceae family by a phylogenetic analysis.