6SJL

Structure of the Tle1 effector bound to the VgrG spike from the Type 6 secretion system

Summary for 6SJL

• Entry DOI: 10.2210/pdb6sjl/pdb
• EMDB information: 10218
• Descriptor: Putative type VI secretion protein (2 entities in total)
• Functional Keywords: hydrolase, toxin, lipase, effector, bacterial
• Biological source: Escherichia coli; More
• Total number of polymer chains: 6
• Total formula weight: 465239.92

Authors

Rapisarda, C.,Fronzes, R. (deposition date: 2019-08-13, release date: 2020-04-29, Last modification date: 2024-05-22)

Primary citation

Flaugnatti, N.,Rapisarda, C.,Rey, M.,Beauvois, S.G.,Nguyen, V.A.,Canaan, S.,Durand, E.,Chamot-Rooke, J.,Cascales, E.,Fronzes, R.,Journet, L.
Structural basis for loading and inhibition of a bacterial T6SS phospholipase effector by the VgrG spike.
Embo J., 39:e104129-e104129, 2020

PubMed Abstract: The bacterial type VI secretion system (T6SS) is a macromolecular machine that injects effectors into prokaryotic and eukaryotic cells. The mode of action of the T6SS is similar to contractile phages: the contraction of a sheath structure pushes a tube topped by a spike into target cells. Effectors are loaded onto the spike or confined into the tube. In enteroaggregative Escherichia coli, the Tle1 phospholipase binds the C-terminal extension of the VgrG trimeric spike. Here, we purify the VgrG-Tle1 complex and show that a VgrG trimer binds three Tle1 monomers and inhibits their activity. Using covalent cross-linking coupled to high-resolution mass spectrometry, we provide information on the sites of contact and further identify the requirement for a Tle1 N-terminal secretion sequence in complex formation. Finally, we report the 2.6-Å-resolution cryo-electron microscopy tri-dimensional structure of the (VgrG) -(Tle1) complex revealing how the effector binds its cargo, and how VgrG inhibits Tle1 phospholipase activity. The inhibition of Tle1 phospholipase activity once bound to VgrG suggests that Tle1 dissociation from VgrG is required upon delivery.

PubMed: 32350888
DOI: 10.15252/embj.2019104129

Experimental method

ELECTRON MICROSCOPY (2.6 Å)