Towards a complete structural deciphering of Type VI secretion system

van Son Nguyen (1) , Badreddine Douzi (2) , Eric Durand (2) , Alain Roussel (3) , E. Cascales (2) , Christian Cambillau (3)

1 AFMB - Architecture et fonction des macromolécules biologiques
2 LISM - Laboratoire d'ingénierie des systèmes macromoléculaires
3 AFMB - Architecture et fonction des macromolécules biologiques

The Type VI secretion system (T6SS) is a dynamic nanomachine present in many Gram-negative bacteria. Using a contraction mechanism similar to that of myophages, bacteriocins or anti-feeding prophages, it injects toxic effectors into both eukaryotic and prokaryotic cells. T6SS assembles three large ensembles: the trans-membrane complex (TMC), the baseplate and the tail. Recently, the tail structure has been elucidated by cryo electron microscopy (cryoEM) in extended and contracted forms. The structure of the trans-membrane complex has been deciphered using a combination of X-ray crystallography and EM. However, the structural characterisation of the baseplate lags behind and should be the target of future studies. Finally, cryo-tomography should provide low/medium resolution maps allowing to assemble the different parts ultimately leading to a complete structural description of T6SS.

Keywords: Bacterial Proteins/*chemistry/ultrastructure; Cryoelectron Microscopy; Crystallography, X-Ray; Gram-Negative Bacteria/*chemistry/ultrastructure; Type VI Secretion Systems/*chemistry/ultrastructure

Keywords: Models, Molecular; Protein Conformation

Domains: Life Sciences [q-bio]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Biochemistry [q-bio.BM]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Molecular biology; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Structural Biology [q-bio.BM]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Biophysics; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Molecular Networks [q-bio.MN]; Life Sciences [q-bio]; Microbiology and Parasitology; Bacteriology

van Son Nguyen, Badreddine Douzi, Eric Durand, Alain Roussel, E. Cascales, et al.. Towards a complete structural deciphering of Type VI secretion system. Current Opinion in Structural Biology, 2018, 49, pp.77 - 84. ⟨10.1016/j.sbi.2018.01.007⟩. ⟨hal-01780753⟩