3WZ3

Structure of a periplasmic fragment of TraM

Summary for 3WZ3

• Entry DOI: 10.2210/pdb3wz3/pdb
• Related: 3WZ3 3WZ5
• Descriptor: TraM protein, SULFATE ION (3 entities in total)
• Functional Keywords: type ivb secretion, unknown function
• Biological source: Plasmid R64
• Total number of polymer chains: 1
• Total formula weight: 16539.55

Authors

Kuroda, T.,Kubori, T.,Uchida, Y.,Nagai, H.,Imada, K. (deposition date: 2014-09-18, release date: 2015-06-10, Last modification date: 2024-10-30)

Primary citation

Kuroda, T.,Kubori, T.,Thanh Bui, X.,Hyakutake, A.,Uchida, Y.,Imada, K.,Nagai, H.
Molecular and structural analysis of Legionella DotI gives insights into an inner membrane complex essential for type IV secretion
Sci Rep, 5:10912-10912, 2015

PubMed Abstract: 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.

PubMed: 26039110
DOI: 10.1038/srep10912

Experimental method

X-RAY DIFFRACTION (1.5 Å)