Structural basis for loading and inhibition of a bacterial T6SS phospholipase effector by the VgrG spike

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 E. 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 forma

SUBMITTER: Dr. Nicolas Flaugnatti 

PROVIDER: S-SCDT-EMBOJ-2019-104129 | biostudies-other |

REPOSITORIES: biostudies-other