1YJ7

Crystal structure of enteropathogenic E.coli (EPEC) type III secretion system protein EscJ

Summary for 1YJ7

• Entry DOI: 10.2210/pdb1yj7/pdb
• Descriptor: escJ, PHOSPHATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: mixed alpha/beta, extended linker, protein transport
• Biological source: Escherichia coli
• Total number of polymer chains: 4
• Total formula weight: 74636.16

Authors

Yip, C.K.,Kimbrough, T.G.,Felise, H.B.,Vuckovic, M.,Thomas, N.A.,Pfuetzner, R.A.,Frey, E.A.,Finlay, B.B.,Miller, S.I.,Strynadka, N.C.J. (deposition date: 2005-01-13, release date: 2005-06-07, Last modification date: 2024-02-14)

Primary citation

Yip, C.K.,Kimbrough, T.G.,Felise, H.B.,Vuckovic, M.,Thomas, N.A.,Pfuetzner, R.A.,Frey, E.A.,Finlay, B.B.,Miller, S.I.,Strynadka, N.C.
Structural characterization of the molecular platform for type III secretion system assembly.
Nature, 435:702-707, 2005

PubMed Abstract: Type III secretion systems (TTSSs) are multi-protein macromolecular 'machines' that have a central function in the virulence of many Gram-negative pathogens by directly mediating the secretion and translocation of bacterial proteins (termed effectors) into the cytoplasm of eukaryotic cells. Most of the 20 unique structural components constituting this secretion apparatus are highly conserved among animal and plant pathogens and are also evolutionarily related to proteins in the flagellar-specific export system. Recent electron microscopy experiments have revealed the gross 'needle-shaped' morphology of the TTSS, yet a detailed understanding of the structural characteristics and organization of these protein components within the bacterial membranes is lacking. Here we report the 1.8-A crystal structure of EscJ from enteropathogenic Escherichia coli (EPEC), a member of the YscJ/PrgK family whose oligomerization represents one of the earliest events in TTSS assembly. Crystal packing analysis and molecular modelling indicate that EscJ could form a large 24-subunit 'ring' superstructure with extensive grooves, ridges and electrostatic features. Electron microscopy, labelling and mass spectrometry studies on the orthologous Salmonella typhimurium PrgK within the context of the assembled TTSS support the stoichiometry, membrane association and surface accessibility of the modelled ring. We propose that the YscJ/PrgK protein family functions as an essential molecular platform for TTSS assembly.

PubMed: 15931226
DOI: 10.1038/nature03554

Experimental method

X-RAY DIFFRACTION (1.8 Å)