Exploitation of an iron transporter for bacterial protein antibiotic import

White, P; Joshi, A; Rassam, P; Housden, NG; Kaminska, R; Goult, JD; Redfield, C; McCaughey, LC; Walker, D; Mohammed, S; Kleanthous, C

Exploitation of an iron transporter for bacterial protein antibiotic import

White, P Joshi, A Rassam, P Housden, NG Kaminska, R Goult, JD Redfield, C McCaughey, LC

Walker, D Mohammed, S Kleanthous, C

Permalink

Publication Type:: Journal Article
Citation:: Proceedings of the National Academy of Sciences of the United States of America, 2017, 114 (45), pp. 12051 - 12056
Issue Date:: 2017-11-07

Open Access

Copyright Clearance Process

Recently Added
In Progress
Open Access

This item is open access.

Adobe PDF

Download Accepted Manuscript VersionAdobe PDF (1.36 MB)

View on publisher's site

View statistics

Full metadata record

Field	Value	Language
dc.contributor.author	White, P	en_US
dc.contributor.author	Joshi, A	en_US
dc.contributor.author	Rassam, P	en_US
dc.contributor.author	Housden, NG	en_US
dc.contributor.author	Kaminska, R	en_US
dc.contributor.author	Goult, JD	en_US
dc.contributor.author	Redfield, C	en_US
dc.contributor.author	McCaughey, LC https://orcid.org/0000-0001-5897-0163	en_US
dc.contributor.author	Walker, D	en_US
dc.contributor.author	Mohammed, S	en_US
dc.contributor.author	Kleanthous, C	en_US
dc.date.issued	2017-11-07	en_US
dc.identifier.citation	Proceedings of the National Academy of Sciences of the United States of America, 2017, 114 (45), pp. 12051 - 12056	en_US
dc.identifier.issn	0027-8424	en_US
dc.identifier.uri	http://hdl.handle.net/10453/122006
dc.description.abstract	© 2017, National Academy of Sciences. All rights reserved. Unlike their descendants, mitochondria and plastids, bacteria do not have dedicated protein import systems. However, paradoxically, import of protein bacteriocins, the mechanisms of which are poorly understood, underpins competition among pathogenic and commensal bacteria alike. Here, using X-ray crystallography, isothermal titration calorimetry, confocal fluorescence microscopy, and in vivo photoactivatable cross-linking of stalled translocation intermediates, we demonstrate how the iron transporter FpvAI in the opportunistic pathogen Pseudomonas aeruginosa is hijacked to translocate the bacteriocin pyocin S2 (pyoS2) across the outer membrane (OM). FpvAI is a TonB-dependent transporter (TBDT) that actively imports the small siderophore ferripyoverdine (Fe-Pvd) by coupling to the proton motive force (PMF) via the inner membrane (IM) protein TonB1. The crystal structure of the N-terminal domain of pyoS2 (pyoS2NTD) bound to FpvAI (Kd = 240 pM) reveals that the pyocin mimics Fe-Pvd, inducing the same conformational changes in the receptor. Mimicry leads to fluorescently labeled pyoS2NTD being imported into FpvAI-expressing P. aeruginosa cells by a process analogous to that used by bona fide TBDT ligands. PyoS2NTD induces unfolding by TonB1 of a force-labile portion of the plug domain that normally occludes the central channel of FpvAI. The pyocin is then dragged through this narrow channel following delivery of its own TonB1-binding epitope to the periplasm. Hence, energized nutrient transporters in bacteria also serve as rudimentary protein import systems, which, in the case of FpvAI, results in a protein antibiotic 60-fold bigger than the transporter’s natural substrate being translocated across the OM.	en_US
dc.relation.ispartof	Proceedings of the National Academy of Sciences of the United States of America	en_US
dc.relation.isbasedon	10.1073/pnas.1713741114	en_US
dc.subject.mesh	Periplasm	en_US
dc.subject.mesh	Pseudomonas aeruginosa	en_US
dc.subject.mesh	Iron	en_US
dc.subject.mesh	Bacterial Outer Membrane Proteins	en_US
dc.subject.mesh	Bacteriocins	en_US
dc.subject.mesh	Membrane Transport Proteins	en_US
dc.subject.mesh	Siderophores	en_US
dc.subject.mesh	Anti-Bacterial Agents	en_US
dc.subject.mesh	Crystallography, X-Ray	en_US
dc.subject.mesh	Biological Transport	en_US
dc.subject.mesh	Protein Transport	en_US
dc.title	Exploitation of an iron transporter for bacterial protein antibiotic import	en_US
dc.type	Journal Article
utslib.citation.volume	45	en_US
utslib.citation.volume	114	en_US
utslib.for	0303 Macromolecular and Materials Chemistry	en_US
utslib.for	MD Multidisciplinary	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Strength - ithree - Institute of Infection, Immunity and Innovation
utslib.copyright.status	open_access
pubs.issue	45	en_US
pubs.publication-status	Published	en_US
pubs.volume	114	en_US

Abstract:

© 2017, National Academy of Sciences. All rights reserved. Unlike their descendants, mitochondria and plastids, bacteria do not have dedicated protein import systems. However, paradoxically, import of protein bacteriocins, the mechanisms of which are poorly understood, underpins competition among pathogenic and commensal bacteria alike. Here, using X-ray crystallography, isothermal titration calorimetry, confocal fluorescence microscopy, and in vivo photoactivatable cross-linking of stalled translocation intermediates, we demonstrate how the iron transporter FpvAI in the opportunistic pathogen Pseudomonas aeruginosa is hijacked to translocate the bacteriocin pyocin S2 (pyoS2) across the outer membrane (OM). FpvAI is a TonB-dependent transporter (TBDT) that actively imports the small siderophore ferripyoverdine (Fe-Pvd) by coupling to the proton motive force (PMF) via the inner membrane (IM) protein TonB1. The crystal structure of the N-terminal domain of pyoS2 (pyoS2NTD) bound to FpvAI (Kd = 240 pM) reveals that the pyocin mimics Fe-Pvd, inducing the same conformational changes in the receptor. Mimicry leads to fluorescently labeled pyoS2NTD being imported into FpvAI-expressing P. aeruginosa cells by a process analogous to that used by bona fide TBDT ligands. PyoS2NTD induces unfolding by TonB1 of a force-labile portion of the plug domain that normally occludes the central channel of FpvAI. The pyocin is then dragged through this narrow channel following delivery of its own TonB1-binding epitope to the periplasm. Hence, energized nutrient transporters in bacteria also serve as rudimentary protein import systems, which, in the case of FpvAI, results in a protein antibiotic 60-fold bigger than the transporter’s natural substrate being translocated across the OM.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/122006