2JW1

Structural characterization of the type III pilotin-secretin interaction in Shigella flexneri by NMR spectroscopy

Summary for 2JW1

• Entry DOI: 10.2210/pdb2jw1/pdb
• NMR Information: BMRB: 15504
• Descriptor: Lipoprotein mxiM, Outer membrane protein mxiD (2 entities in total)
• Functional Keywords: protein-protein interaction, lipoprotein, membrane, outer membrane, palmitate, plasmid, virulence, protein transport, transport, membrane protein
• Biological source: Shigella flexneri; More
• Total number of polymer chains: 2
• Total formula weight: 15035.20

Authors

Okon, M.S.,Lario, P.I.,Creagh, L.,Jung, Y.M.T.,Maurelli, A.T.,Strynadka, N.C.J.,McIntosh, L.P. (deposition date: 2007-10-02, release date: 2008-09-02, Last modification date: 2024-11-27)

Primary citation

Okon, M.,Moraes, T.F.,Lario, P.I.,Creagh, A.L.,Haynes, C.A.,Strynadka, N.C.,McIntosh, L.P.
Structural Characterization of the Type-III Pilot-Secretin Complex from Shigella flexneri
Structure, 16:1544-1554, 2008

PubMed Abstract: Assembly of the type-III secretion apparatus, which translocates proteins through both membranes of Gram-negative bacterial pathogens into host cells, requires the formation of an integral outer-membrane secretin ring. Typically, a small lipidated pilot protein is necessary for the stabilization and localization of this ring. Using NMR spectroscopy, we demonstrate that the C-terminal residues 553-570 of the Shigella flexneri secretin MxiD encompass the minimal binding domain for its cognate pilot MxiM. Although unstructured in isolation, upon complex formation with MxiM, these residues fold into an amphipathic turn-helix motif that caps the elongated hydrophobic cavity of the cracked beta-barrel pilot. Along with a rearrangement of core aromatic residues, this prevents the binding of lipids within the cavity. The mutually exclusive association of lipids and MxiD with MxiM establishes a framework for understanding the role of a pilot in the outer-membrane insertion and multimerization of the secretin ring.

PubMed: 18940609
DOI: 10.1016/j.str.2008.08.006

Experimental method

SOLUTION NMR