4Y7O: T6ss Protein Tssm C-terminal Domain (869-1107) From Eaec

Bacteria share their ecological niches with other microbes. The bacterial type VI secretion system is one of the key players in microbial competition, as well as being an important virulence determinant during bacterial infections. It assembles a nano-crossbow-like structure in the cytoplasm of the attacker cell that propels an arrow made of a haemolysin co-regulated protein (Hcp) tube and a valine-glycine repeat protein G (VgrG) spike and punctures the prey's cell wall. The nano-crossbow is stably anchored to the cell envelope of the attacker by a membrane core complex. Here we show that this complex is assembled by the sequential addition of three type VI subunits (Tss)-TssJ, TssM and TssL-and present a structure of the fully assembled complex at 11.6 A resolution, determined by negative-stain electron microscopy. With overall C5 symmetry, this 1.7-megadalton complex comprises a large base in the cytoplasm. It extends in the periplasm via ten arches to form a double-ring structure containing the carboxy-terminal domain of TssM (TssMct) and TssJ that is anchored in the outer membrane. The crystal structure of the TssMct-TssJ complex coupled to whole-cell accessibility studies suggest that large conformational changes induce transient pore formation in the outer membrane, allowing passage of the attacking Hcp tube/VgrG spike.
PDB ID: 4Y7ODownload
MMDB ID: 131454
PDB Deposition Date: 2015/2/15
Updated in MMDB: 2015/08
Experimental Method:
x-ray diffraction
Resolution: 2.24  Å
Source Organism:
Escherichia coli 1-176-05_S3_C1
Similar Structures:
Biological Unit for 4Y7O: dimeric; determined by author and by software (PISA)
Molecular Components in 4Y7O
Label Count Molecule
Proteins (2 molecules)
Type VI Secretion Protein Icmf
Molecule annotation
Type VI Secretion System Protein Vasd
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB