Activity and Crystal Structure of the Adherent-Invasive Escherichia coli Tle3/Tli3 T6SS Effector/Immunity Complex Determined Using an AlphaFold2 Predicted Model.

ABSTRACT: The type VI secretion system (T6SS) delivers enzymatic effectors into target cells to destroy them. Cells of the same strain protect themselves against effectors with immunity proteins that specifically inhibit effectors. Here, we report the identification and characterization of a Tle3 phospholipase effector and its cognate immunity protein Tli3-an outer membrane lipoprotein from adherent-invasive Escherichia coli (AIEC). Enzymatic assays demonstrate that purified Tle3^AIEC has a phospholipase A1, and not A2, activity and that its toxicity is neutralized by the cognate immunity protein Tli3^AIEC. Tli3^AIEC binds Tle3 in a 1:1 stoichiometric ratio. Tle3^AIEC, Tli3^AIEC and the Tle3^AIEC-Tli3^AIEC complex were puri

SUBMITTER: Le TTH 

PROVIDER: S-EPMC9860674 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature