Structural insights into substrate recognition by the type VII secretion system.

ABSTRACT: Type VII secretion systems (T7SSs) are found in many disease related bacteria including Mycobacterium tuberculosis (Mtb). ESX-1 [early secreted antigen 6 kilodaltons (ESAT-6) system 1] is one of the five subtypes (ESX-1~5) of T7SSs in Mtb, where it delivers virulence factors into host macrophages during infection. However, little is known about the molecular details as to how this occurs. Here, we provide high-resolution crystal structures of the C-terminal ATPase₃ domains of EccC subunits from four different Mtb T7SS subtypes. These structures adopt a classic RecA-like ɑ/β fold with a conserved Mg-ATP binding site. The structure of EccCb1 in complex with the C-terminal peptide of EsxB identifies the location of substrate recognition site and shows how the specific signaling mod

SUBMITTER: Wang S 

PROVIDER: S-EPMC6954902 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature