8sl0 | pdb_00008sl0
Structure of a bacterial gasdermin slinky-like oligomer
Structural highlights
FunctionGSDM_VITXG Precursor of a pore-forming protein involved in defense against bacteriophages (By similarity). Expression of bGSDM and the neighboring protease gene (Ga0334635_1659) is toxic in E.coli (PubMed:35025633). Cleavage of this precursor by its dedicated protease releases the active moiety (gasdermin bGSDM, N-terminus) which inserts into membranes, forming pores and triggering cell death (Probable) (PubMed:38509367).[UniProtKB:A0A0S2DNG5][UniProtKB:P0DV48][1] [2] Pore-forming protein that causes membrane permeabilization, probably via a pyroptosis-like activity (Probable) (PubMed:38509367). Makes ring-like pores with an interior pore diameter of 200-300 Angstroms, when integrated in liposomes (PubMed:38509367).[3] [4] Publication Abstract from PubMedIn response to pathogen infection, gasdermin (GSDM) proteins form membrane pores that induce a host cell death process called pyroptosis(1-3). Studies of human and mouse GSDM pores have revealed the functions and architectures of assemblies comprising 24 to 33 protomers(4-9), but the mechanism and evolutionary origin of membrane targeting and GSDM pore formation remain unknown. Here we determine a structure of a bacterial GSDM (bGSDM) pore and define a conserved mechanism of pore assembly. Engineering a panel of bGSDMs for site-specific proteolytic activation, we demonstrate that diverse bGSDMs form distinct pore sizes that range from smaller mammalian-like assemblies to exceptionally large pores containing more than 50 protomers. We determine a cryo-electron microscopy structure of a Vitiosangium bGSDM in an active 'slinky'-like oligomeric conformation and analyse bGSDM pores in a native lipid environment to create an atomic-level model of a full 52-mer bGSDM pore. Combining our structural analysis with molecular dynamics simulations and cellular assays, our results support a stepwise model of GSDM pore assembly and suggest that a covalently bound palmitoyl can leave a hydrophobic sheath and insert into the membrane before formation of the membrane-spanning beta-strand regions. These results reveal the diversity of GSDM pores found in nature and explain the function of an ancient post-translational modification in enabling programmed host cell death. Structure and assembly of a bacterial gasdermin pore.,Johnson AG, Mayer ML, Schaefer SL, McNamara-Bordewick NK, Hummer G, Kranzusch PJ Nature. 2024 Apr;628(8008):657-663. doi: 10.1038/s41586-024-07216-3. Epub 2024 , Mar 20. PMID:38509367[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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