PT  - JOURNAL ARTICLE
AU  - Hannah M. Behrens
AU  - Edward D. Lowe
AU  - Joseph Gault
AU  - Nicholas G. Housden
AU  - Renata Kaminska
AU  - T. Moritz Weber
AU  - Catriona M A Thompson
AU  - Gaëtan L. A. Mislin
AU  - Isabelle J. Schalk
AU  - Daniel Walker
AU  - Carol V. Robinson
AU  - Colin Kleanthous
TI  - Pyocin S5 import into <em>Pseudomonas aeruginosa</em> reveals a generic mode of bacteriocin transport
AID  - 10.1101/856047
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 856047
4099  - http://biorxiv.org/content/early/2019/11/26/856047.short
4100  - http://biorxiv.org/content/early/2019/11/26/856047.full
AB  - Pyocin S5 (PyoS5) is a potent protein bacteriocin that eradicates the human pathogen P. aeruginosa in animal infection models, but its import mechanism is poorly understood. Here, using crystallography, biophysical and biochemical analysis and live-cell imaging, we define the entry process of PyoS5 and reveal links to the transport mechanisms of other bacteriocins. In addition to its C-terminal pore-forming domain, elongated PyoS5 comprises two novel tandemly repeated kinked three helix bundle domains that structure-based alignments identify as key import domains in other pyocins. The central domain binds the lipid-bound common polysaccharide antigen, allowing the pyocin to accumulate on the cell surface. The N-terminal domain binds the ferric pyochelin transporter FptA while its associated disordered region binds the inner membrane protein TonB1, which together drive import of the bacteriocin across the outer membrane. Finally, we identify the minimal requirements for sensitizing Escherichia coli towards PyoS5, as well as other pyocins, and suggest that a generic pathway likely underpins the import of all TonB-dependent bacteriocins across the outer membrane of Gram-negative bacteria.