PT  - JOURNAL ARTICLE
AU  - Paweena Chaoprasid
AU  - Peer Lukat
AU  - Sabrina Mühlen
AU  - Janina N. G. Schweer
AU  - Thomas V. Heidler
AU  - Emerich-Mihai Gazdag
AU  - Theresia E. B. Stradal
AU  - Petra Dersch
AU  - Wulf Blankenfeldt
TI  - The structure of bacterial toxin CNF<sub>Y</sub> reveals requirements for secretion, host cell recognition and endosomal release
AID  - 10.1101/2020.04.07.029181
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.04.07.029181
4099  - http://biorxiv.org/content/early/2020/04/08/2020.04.07.029181.short
4100  - http://biorxiv.org/content/early/2020/04/08/2020.04.07.029181.full
AB  - Cytotoxic necrotizing factors (CNFs) are single-chain exotoxins. They are secreted by several bacterial pathogens to modulate cytokinetic/oncogenic and inflammatory processes through activation host cell Rho-GTPases, but their secretion-translocation mechanism still remains an enigma. Here, we determined the crystal structure of full-length Yersinia pseudotuberculosis CNFY, revealing five separate domains (D1-D5) of which D1-D3 act as translocation module for the catalytic unit (D4-5) and for other fused reporter proteins. By integrating structural and functional data, we suggest a model in which the α-helical D1 domain constitutes a membrane-spanning translocation unit. This unit promotes bacterial export and exposes the host cell recognition sites of D2. Receptor binding then triggers endosomal uptake, release and structural reorientation of the catalytic unit implicating D3. Sequence comparison also suggests that this translocation mechanism is used by many other bacterial proteins and could be employed as universal drug delivery tool.