
Open access
Date
2019Type
- Journal Article
Abstract
Contractile injection systems (CISs) mediate cell-cell interactions by a phage tail-like apparatus. Their conserved mechanism relies on the anchoring of the proximal end of a sheath-tube module to a membrane, followed by contraction of the sheath towards the attachment site and ejection of the inner tube. Here we reveal a major variation of the CIS mechanism in the type six secretion system (T6SS) of enteroaggregative Escherichia coli (EAEC). We show that both ends of the sheath-tube module are attached to opposite sides of the cell, enabling the structure to contract in two opposite directions. The protein TssA1 mediates the interaction of the distal end with the cell envelope, the termination of tail elongation, and non-canonical contraction towards the distal end. We provide a framework for the molecular processes at the T6SS distal end. Further research will address whether bidirectional contraction allows for bidirectional effector secretion. The unrecognized concept of non-canonical contractions could be relevant to biofilms of the human intestine. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000338818Publication status
publishedExternal links
Journal / series
Nature CommunicationsVolume
Pages / Article No.
Publisher
NatureOrganisational unit
09463 - Pilhofer, Martin / Pilhofer, Martin
Funding
679209 - Multiscale model of bacterial cell-cell interactions (EC)
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