Abstract

The Ff family of filamentous bacteriophages infect gram-negative bacteria, but do not cause lysis of their host cell. Instead, new virions are extruded via the phage-encoded pIV protein, which has homology with bacterial secretins. Here, we determine the structure of pIV from the f1 filamentous bacteriophage at 2.7 Å resolution by cryo-electron microscopy, the first near-atomic structure of a phage secretin. Fifteen f1 pIV subunits assemble to form a gated channel in the bacterial outer membrane, with associated soluble domains projecting into the periplasm. We model channel opening and propose a mechanism for phage egress. By single-cell microfluidics experiments, we demonstrate the potential for secretins such as pIV to be used as adjuvants to increase the uptake and efficacy of antibiotics in bacteria. Finally, we compare the f1 pIV structure to its homologues to reveal similarities and differences between phage and bacterial secretins.

New virions of Ff bacteriophages are extruded from the host cell via the channel built from phage protein pIV, homologous to bacterial secretins. Here, the authors report the structure of this channel from the f1 filamentous bacteriophage and propose its use as an adjuvant to increase the uptake and efficacy of antibiotics.

Details

Title
CryoEM structure of the outer membrane secretin channel pIV from the f1 filamentous bacteriophage
Author
Conners, Rebecca 1   VIAFID ORCID Logo  ; McLaren, Mathew 1 ; Łapińska Urszula 1 ; Sanders, Kelly 1 ; Stone M Rhia L 2 ; Blaskovich Mark A T 2   VIAFID ORCID Logo  ; Pagliara Stefano 1 ; Daum Bertram 1   VIAFID ORCID Logo  ; Rakonjac Jasna 3   VIAFID ORCID Logo  ; Gold Vicki A M 1   VIAFID ORCID Logo 

 University of Exeter, Living Systems Institute, Exeter, UK (GRID:grid.8391.3) (ISNI:0000 0004 1936 8024); University of Exeter, College of Life and Environmental Sciences, Geoffrey Pope, Exeter, UK (GRID:grid.8391.3) (ISNI:0000 0004 1936 8024) 
 The University of Queensland, Centre for Superbug Solutions, Institute for Molecular Bioscience, Brisbane, Australia (GRID:grid.1003.2) (ISNI:0000 0000 9320 7537) 
 Massey University, School of Fundamental Sciences, Palmerston North, New Zealand (GRID:grid.148374.d) (ISNI:0000 0001 0696 9806) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2591866904
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.