Publication Date:
2014-02-28
Description:
Tripartite Tc toxin complexes of bacterial pathogens perforate the host membrane and translocate toxic enzymes into the host cell, including in humans. The underlying mechanism is complex but poorly understood. Here we report the first, to our knowledge, high-resolution structures of a TcA subunit in its prepore and pore state and of a complete 1.7 megadalton Tc complex. The structures reveal that, in addition to a translocation channel, TcA forms four receptor-binding sites and a neuraminidase-like region, which are important for its host specificity. pH-induced opening of the shell releases an entropic spring that drives the injection of the TcA channel into the membrane. Binding of TcB/TcC to TcA opens a gate formed by a six-bladed beta-propeller and results in a continuous protein translocation channel, whose architecture and properties suggest a novel mode of protein unfolding and translocation. Our results allow us to understand key steps of infections involving Tc toxins at the molecular level.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Meusch, Dominic -- Gatsogiannis, Christos -- Efremov, Rouslan G -- Lang, Alexander E -- Hofnagel, Oliver -- Vetter, Ingrid R -- Aktories, Klaus -- Raunser, Stefan -- England -- Nature. 2014 Apr 3;508(7494):61-5. doi: 10.1038/nature13015. Epub 2014 Feb 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany [2]. ; Institut fur Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universitat Freiburg, 79104 Freiburg, Germany. ; Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany. ; Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany. ; 1] Institut fur Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universitat Freiburg, 79104 Freiburg, Germany [2] BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universitat Freiburg, 79104 Freiburg, Germany. ; 1] Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany [2] Institute of Chemistry and Biochemistry, Freie Universitat Berlin, Thielallee 63, 14195 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24572368" target="_blank"〉PubMed〈/a〉
Keywords:
ADP Ribose Transferases/metabolism
;
Bacterial Toxins/*chemistry/*metabolism
;
Binding Sites
;
Cell Membrane/metabolism
;
Crystallography, X-Ray
;
Host Specificity
;
Hydrogen-Ion Concentration
;
Models, Molecular
;
Neuraminidase/chemistry
;
Photorhabdus/*chemistry
;
Porosity
;
Protein Structure, Tertiary
;
Protein Subunits/chemistry/metabolism
;
Protein Transport
;
Protein Unfolding
;
Structure-Activity Relationship
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
