preprints.org > doi: 10.20944/preprints201910.0325.v1

Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Version 1 : Received: 27 October 2019 / Approved: 29 October 2019 / Online: 29 October 2019 (09:51:30 CET)

The toxin-antitoxin (TA) systems have been attracting attention due to their role in regulating prokaryotic cell responses to stress and their biotechnological potential. Much recognition has been given to type II TA system of mesophiles, but so far, limited attention has been given to thermophiles. Here, we are presenting the putative type II TA families encoded on the genomes of four Geobacillus strains. We employed the TA finder tool to mine for TA-coding genes and manually curated the results using various tools. We identified 28 putative TA pairs, distributed over 8 TA families. Among the identified TAs, 15 represent putative novel toxins and antitoxins that have been overlooked or annotated as hypothetical proteins in their genome records. We also identified a potentially new TA composite, AbrB-ParE. Furthermore, we are suggesting the Geobacillus acetyltransferase toxin-antitoxin (GacTA) family which potentially represents one of the unique TA families that has a reverse gene order. Moreover, we are proposing a hypothesis on the regulation of the xre-cog2856 gene expression, which seems to involve c-di-AMP. This study aims for highlighting the significance of studying TAs in Geobacillus, since they have special features. It also aims for facilitating future experimental research.

AbrB-ParE; c-di-AMP; Geobacillus kaustophilus; Geobacillus thermodenitrificans; Geobacillus thermoleovorans; Geobacillus sp. ZGt-1; GNAT-HTH; (p)ppGpp; MNT-HEPN; XRE-COG2856