Cryo-EM reveals the membrane-binding phenomenon of EspB, a virulence factor of the mycobacterial type VII secretion system.

ABSTRACT: Mycobacterium tuberculosis (Mtb) utilizes sophisticated machinery called the type VII secretion system to translocate virulence factors across its complex lipid membrane. EspB, a ∼36 kDa secreted substrate of the ESX-1 apparatus, was shown to cause ESAT-6-independent host cell death. Despite the current wealth of high-resolution structural information of the ordered N-terminal domain, the mechanism of EspB-mediated virulence remains poorly characterized. Here, we document EspB interaction with phosphatidic acid (PA) and phosphatidylserine (PS) in the context of membranes, through a biophysical approach including transmission electron microscopy and cryo-EM. We were also able to show PA, PS-dependent conversion of monomers to oligomers at physiological pH. Our data suggest that EspB adheres

SUBMITTER: Sengupta N 

PROVIDER: S-EPMC10140165 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature