Trokter, M;
Waksman, G;
(2018)
Translocation through the conjugative Type 4 secretion system requires unfolding of its protein substrate.
Journal of Bacteriology
, 200
(6)
, Article e00615-17. 10.1128/JB.00615-17.
Preview |
Text
Waksman_J. Bacteriol.-2018-Trokter-.pdf Download (402kB) | Preview |
Abstract
Bacterial conjugation, a mechanism of horizontal gene transfer, is the major means by which antibiotic resistance spreads among bacteria (1, 2). Conjugative plasmids are transferred from one bacterium to another through a type IV secretion system (T4SS) in a form of single-stranded DNA covalently attached to a protein called relaxase. The relaxase is fully functional both in a donor cell (prior to conjugation) and recipient cell (after conjugation). Here we demonstrate that the protein substrate has to unfold for efficient translocation through the conjugative T4SS. Furthermore, we present various relaxase modifications that preserve the function of the relaxase but block substrate translocation. This study brings us a step closer to deciphering the complete mechanism of T4SS substrate translocation, vital for development of new therapies against multidrug-resistant pathogenic bacteria.Importance Conjugation is the principal means by which antibiotic resistance genes spread from one bacterium to another (1, 2). During conjugation, a covalent complex of single-stranded DNA and a protein termed relaxase is transported by a type IV secretion system. To date, it is not known whether the relaxase requires unfolding prior to transport. In this report, we use functional assays to monitor the transport of relaxase wild-type and variants containing unfolding-resistant domains and show that these domains reduce conjugation and protein transport dramatically. Mutations that lower the free energy of unfolding in these domains do not block translocation and can even promote it. We thus conclude that the unfolding of the protein substrate is required during transport.
| Type: | Article |
|---|---|
| Title: | Translocation through the conjugative Type 4 secretion system requires unfolding of its protein substrate |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1128/JB.00615-17 |
| Publisher version: | http://doi.org/10.1128/JB.00615-17 |
| Language: | English |
| Additional information: | Copyright © 2018 Trokter and Waksman. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Structural and Molecular Biology |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10043578 |
Archive Staff Only
 |
View Item |
