In situ and in vitro cryo-EM reveal structures of mycobacterial encapsulin assembly intermediates.

ABSTRACT: Prokaryotes rely on proteinaceous compartments such as encapsulin to isolate harmful reactions. Encapsulin are widely expressed by bacteria, including the Mycobacteriaceae, which include the human pathogens Mycobacterium tuberculosis and Mycobacterium leprae. Structures of fully assembled encapsulin shells have been determined for several species, but encapsulin assembly and cargo encapsulation are still poorly characterised, because of the absence of encapsulin structures in intermediate assembly states. We combine in situ and in vitro structural electron microscopy to show that encapsulins are dynamic assemblies with intermediate states of cargo encapsulation and shell assembly. Using cryo-focused ion beam (FIB) lamella preparation and cryo-electron tomography (CET), we directly visualis

SUBMITTER: Berger C 

PROVIDER: S-EPMC11830004 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature