Reversible regulation of conjugation of Bacillus subtilis plasmid pLS20 by the quorum sensing peptide responsive anti-repressor RappLS20

Singh, P. K. et al. (2020) Reversible regulation of conjugation of Bacillus subtilis plasmid pLS20 by the quorum sensing peptide responsive anti-repressor RappLS20. Nucleic Acids Research, 48(19), pp. 10785-10801. (doi: 10.1093/nar/gkaa797) (PMID:33045732) (PMCID:PMC7641744)

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Quorum sensing plays crucial roles in bacterial communication including in the process of conjugation, which has large economical and health-related impacts by spreading antibiotic resistance. The conjugative Bacillus subtilis plasmid pLS20 uses quorum sensing to determine when to activate the conjugation genes. The main conjugation promoter, Pc, is by default repressed by a regulator RcopLS20 involving DNA looping. A plasmid-encoded signalling peptide, Phr*pLS20, inactivates the anti-repressor of RcopLS20, named RappLS20, which belongs to the large group of RRNPP family of regulatory proteins. Here we show that DNA looping occurs through interactions between two RcopLS20 tetramers, each bound to an operator site. We determined the relative promoter strengths for all the promoters involved in synthesizing the regulatory proteins of the conjugation genes, and constructed an in vivo system uncoupling these regulatory genes to show that RappLS20 is sufficient for activating conjugation in vivo. We also show that RappLS20 actively detaches RcopLS20 from DNA by preferentially acting on the RcopLS20 molecules involved in DNA looping, resulting in sequestration but not inactivation of RcopLS20. Finally, results presented here in combination with our previous results show that activation of conjugation inhibits competence and competence development inhibits conjugation, indicating that both processes are mutually exclusive.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Serrano, Dr Ester
Authors: Singh, P. K., Serrano, E., Ramachandran, G., Miguel-Arribas, A., Gago-Cordoba, C., Val-Calvo, J., López-Pérez, A., Alfonso, C., Wu, L. J., Luque-Ortega, J. R., and Meijer, W. J.J.
College/School:College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Nucleic Acids Research
Publisher:Oxford University Press
ISSN (Online):1362-4962
Published Online:12 October 2020
Copyright Holders:Copyright © 2020 The Authors
First Published:First published in Nucleic Acids Research 48(19): 10785-10801
Publisher Policy:Reproduced under a Creative Commons License

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