4JIW

c1882 PAAR-repeat protein from Escherichia coli in complex with a VgrG-like beta-helix that is based on a fragment of T4 gp5

Summary for 4JIW

• Entry DOI: 10.2210/pdb4jiw/pdb
• Related: 1K28 4JIV
• Descriptor: Tail-associated lysozyme, Putative uncharacterized protein, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: paar-repeat motif, membrane piercing, type vi secretion system, t6ss spike, cell puncturing device, beta-helix, t4 gp5, vgrg tip, cft073, vgrg protein, hydrolase-protein binding complex, hydrolase/protein binding
• Biological source: Enterobacteria phage T4; More
• Cellular location: Virion : P16009
• Total number of polymer chains: 16
• Total formula weight: 157565.84

Authors

Buth, S.A.,Leiman, P.G.,Shneider, M.M. (deposition date: 2013-03-07, release date: 2013-08-14, Last modification date: 2024-03-20)

Primary citation

Shneider, M.M.,Buth, S.A.,Ho, B.T.,Basler, M.,Mekalanos, J.J.,Leiman, P.G.
PAAR-repeat proteins sharpen and diversify the type VI secretion system spike.
Nature, 500:350-353, 2013

PubMed Abstract: The bacterial type VI secretion system (T6SS) is a large multicomponent, dynamic macromolecular machine that has an important role in the ecology of many Gram-negative bacteria. T6SS is responsible for translocation of a wide range of toxic effector molecules, allowing predatory cells to kill both prokaryotic as well as eukaryotic prey cells. The T6SS organelle is functionally analogous to contractile tails of bacteriophages and is thought to attack cells by initially penetrating them with a trimeric protein complex called the VgrG spike. Neither the exact protein composition of the T6SS organelle nor the mechanisms of effector selection and delivery are known. Here we report that proteins from the PAAR (proline-alanine-alanine-arginine) repeat superfamily form a sharp conical extension on the VgrG spike, which is further involved in attaching effector domains to the spike. The crystal structures of two PAAR-repeat proteins bound to VgrG-like partners show that these proteins sharpen the tip of the T6SS spike complex. We demonstrate that PAAR proteins are essential for T6SS-mediated secretion and target cell killing by Vibrio cholerae and Acinetobacter baylyi. Our results indicate a new model of the T6SS organelle in which the VgrG-PAAR spike complex is decorated with multiple effectors that are delivered simultaneously into target cells in a single contraction-driven translocation event.

PubMed: 23925114
DOI: 10.1038/nature12453

Experimental method

X-RAY DIFFRACTION (3.402 Å)