2UWJ

Structure of the heterotrimeric complex which regulates type III secretion needle formation

Summary for 2UWJ

• Entry DOI: 10.2210/pdb2uwj/pdb
• Descriptor: TYPE III EXPORT PROTEIN PSCE, TYPE III EXPORT PROTEIN PSCF, TYPE III EXPORT PROTEIN PSCG, ... (5 entities in total)
• Functional Keywords: virulence, chaperones, coiled coil, needle formation, type iii secretion, bacterial pathogenicity, chaperone
• Biological source: PSEUDOMONAS AERUGINOSA; More
• Cellular location: Cytoplasm : Q9I317 P95435; Secreted : P95434
• Total number of polymer chains: 3
• Total formula weight: 24063.35

Authors

Quinaud, M.,Ple, S.,Job, V.,Contreras-Martel, C.,Simorre, J.P.,Attree, I.,Dessen, A. (deposition date: 2007-03-22, release date: 2007-05-15, Last modification date: 2024-05-08)

Primary citation

Quinaud, M.,Ple, S.,Job, V.,Contreras-Martel, C.,Simorre, J.P.,Attree, I.,Dessen, A.
Structure of the heterotrimeric complex that regulates type III secretion needle formation.
Proc. Natl. Acad. Sci. U.S.A., 104:7803-7808, 2007

PubMed Abstract: Type III secretion systems (T3SS), found in several Gram-negative pathogens, are nanomachines involved in the transport of virulence effectors directly into the cytoplasm of target cells. T3SS are essentially composed of basal membrane-embedded ring-like structures and a hollow needle formed by a single polymerized protein. Within the bacterial cytoplasm, the T3SS needle protein requires two distinct chaperones for stabilization before its secretion, without which the entire T3SS is nonfunctional. The 2.0-A x-ray crystal structure of the PscE-PscF(55-85)-PscG heterotrimeric complex from Pseudomonas aeruginosa reveals that the C terminus of the needle protein PscF is engulfed within the hydrophobic groove of the tetratricopeptide-like molecule PscG, indicating that the macromolecular scaffold necessary to stabilize the T3SS needle is totally distinct from chaperoned complexes between pilus- or flagellum-forming molecules. Disruption of specific PscG-PscF interactions leads to impairment of bacterial cytotoxicity toward macrophages, indicating that this essential heterotrimer, which possesses homologs in a wide variety of pathogens, is a unique attractive target for the development of novel antibacterials.

PubMed: 17470796
DOI: 10.1073/pnas.0610098104

Experimental method

X-RAY DIFFRACTION (2 Å)