In situ architecture, function, and evolution of a contractile injection system.
Science
; 357(6352): 713-717, 2017 08 18.
Article
in En
| MEDLINE
| ID: mdl-28818949
ABSTRACT
Contractile injection systems mediate bacterial cell-cell interactions by a bacteriophage tail-like structure. In contrast to extracellular systems, the type 6 secretion system (T6SS) is defined by intracellular localization and attachment to the cytoplasmic membrane. Here we used cryo-focused ion beam milling, electron cryotomography, and functional assays to study a T6SS in Amoebophilus asiaticus The in situ architecture revealed three modules, including a contractile sheath-tube, a baseplate, and an anchor. All modules showed conformational changes upon firing. Lateral baseplate interactions coordinated T6SSs in hexagonal arrays. The system mediated interactions with host membranes and may participate in phagosome escape. Evolutionary sequence analyses predicted that T6SSs are more widespread than previously thought. Our insights form the basis for understanding T6SS key concepts and exploring T6SS diversity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacteroidetes
/
Type VI Secretion Systems
/
Amoeba
Language:
En
Journal:
Science
Year:
2017
Document type:
Article
Affiliation country:
Switzerland