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Functional annotation of a novel toxin–antitoxin system Xn-RelT of Xenorhabdus nematophila; a combined in silico and in vitro approach

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Abstract

Toxin–antitoxin (TA) complexes play an important role in stress responses and programmed cell death in bacteria. The RelB-RelE toxin antitoxin system is well studied in Escherichia coli. In this study, we used combined in silico and in vitro approaches to study a novel Xn-RelT toxin from Xenorhabdus nematophila bearing its own antitoxin Xn-RelAT—a RelB homolog of E. coli. The structure for this toxin–antitoxin pair is yet unknown. We generated homology-based models of X. nematophila RelT toxin and antitoxin. The deduced models were further characterized for protein–nucleic acid, protein–protein interactions and gene ontology. A detrimental effect of recombinant Xn-RelT on host E. coli was determined through endogenous toxicity assay. When expressed from a isopropyl β-d-1-thiogalactopyranoside-regulated LacZ promoter, Xn-RelT toxin showed a toxic effect on E. coli cells. These observations imply that the conditional cooperativity governing the Xn-RelT TA operon in X. nematophila plays an important role in stress management and programmed cell death.

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Acknowledgments

The authors thank Science and Engineering Research Board, Department of Science and Technology (DST-SERB), India for financial support for this study. L.K.G. and M.Y. acknowledge DST, Government of India, for a Junior Research Fellowship for this project.

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  1. Lalit Kumar Gautam

    Present address: Department of Biotechnology, Panjab University, Chandigarh, 160014, India

Authors and Affiliations

  1. School of Biotechnology, Gautam Buddha University, Yamuna Expressway, Gautam Buddha Nagar, Greater Noida, Uttar Pradesh, 201312, India

    Lalit Kumar Gautam, Mohit Yadav & Jitendra Singh Rathore

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  1. Lalit Kumar Gautam
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Gautam, L.K., Yadav, M. & Rathore, J.S. Functional annotation of a novel toxin–antitoxin system Xn-RelT of Xenorhabdus nematophila; a combined in silico and in vitro approach. J Mol Model 23, 189 (2017). https://doi.org/10.1007/s00894-017-3361-5

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  • DOI: https://doi.org/10.1007/s00894-017-3361-5

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