1Y9T

Crystal structure of a type III secretion system protein complexed with the lipid, 1-monohexanoyl-2-hydroxy-sn-glycero-3-phosphate

Summary for 1Y9T

• Entry DOI: 10.2210/pdb1y9t/pdb
• Related: 1Y9L
• Descriptor: Lipoprotein mxiM, ACETATE ION, (2R)-2-HYDROXY-3-(PHOSPHONOOXY)PROPYL HEXANOATE, ... (4 entities in total)
• Functional Keywords: mixed alpha/beta, cracked b-barrel fold, lipid binding protein
• Biological source: Shigella flexneri
• Cellular location: Cell outer membrane; Lipid-anchor (Probable): P0A1X2
• Total number of polymer chains: 1
• Total formula weight: 13233.15

Authors

Lario, P.I.,Strynadka, N.C. (deposition date: 2004-12-16, release date: 2005-04-12, Last modification date: 2024-10-16)

Primary citation

Lario, P.I.,Pfuetzner, R.A.,Frey, E.A.,Creagh, L.,Haynes, C.,Maurelli, A.T.,Strynadka, N.C.
Structure and biochemical analysis of a secretin pilot protein.
Embo J., 24:1111-1121, 2005

PubMed Abstract: The ability to translocate virulence proteins into host cells through a type III secretion apparatus (TTSS) is a hallmark of several Gram-negative pathogens including Shigella, Salmonella, Yersinia, Pseudomonas, and enteropathogenic Escherichia coli. In common with other types of bacterial secretion apparatus, the assembly of the TTSS complex requires the preceding formation of its integral outer membrane secretin ring component. We have determined at 1.5 A the structure of MxiM28-142, the Shigella pilot protein that is essential for the assembly and membrane association of the Shigella secretin, MxiD. This represents the first atomic structure of a secretin pilot protein from the several bacterial secretion systems containing an orthologous secretin component. A deep hydrophobic cavity is observed in the novel 'cracked barrel' structure of MxiM, providing a specific binding domain for the acyl chains of bacterial lipids, a proposal that is supported by our various lipid/MxiM complex structures. Isothermal titration analysis shows that the C-terminal domain of the secretin, MxiD525-570, hinders lipid binding to MxiM.

PubMed: 15775974
DOI: 10.1038/sj.emboj.7600610

Experimental method

X-RAY DIFFRACTION (1.87 Å)