3WZ5: Structure Of The Periplasmic Domain Of Doti (crystal Form Ii)

The human pathogen Legionella pneumophila delivers a large array of the effector proteins into host cells using the Dot/Icm type IVB secretion system. Among the proteins composing the Dot/Icm system, an inner membrane protein DotI is known to be crucial for the secretion function but its structure and role in type IV secretion had not been elucidated. We report here the crystal structures of the periplasmic domains of DotI and its ortholog in the conjugation system of plasmid R64, TraM. These structures reveal a striking similarity to VirB8, a component of type IVA secretion systems, suggesting that DotI/TraM is the type IVB counterpart of VirB8. We further show that DotI and its partial paralog DotJ form a stable heterocomplex. R64 TraM, encoded by the conjugative plasmid lacking DotJ ortholog, forms a homo-hexamer. The DotI-DotJ complex is distinct from the core complex, which spans both inner and outer membranes to form a substrate conduit, and seems not to stably associate with the core complex. These results give insight into VirB8-family inner membrane proteins essential for type IV secretion and aid towards understanding the molecular basis of secretion systems essential for bacterial pathogenesis.
PDB ID: 3WZ5Download
MMDB ID: 129865
PDB Deposition Date: 2014/9/18
Updated in MMDB: 2016/07
Experimental Method:
x-ray diffraction
Resolution: 3.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3WZ5: monomeric; determined by software (PISA)
Molecular Components in 3WZ5
Label Count Molecule
Protein (1 molecule)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB