6j0b

Cryo-EM Structure of an Extracellular Contractile Injection System, PVC sheath-tube complex in extended stateCryo-EM Structure of an Extracellular Contractile Injection System, PVC sheath-tube complex in extended state

6j0b, resolution 2.90Å Show:Asymmetric Unit Biological Assembly Structural highlights 6j0b is a 24 chain structure with sequence from Phoaa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: PAU_03352, PA-RVA20-21-0170 (PHOAA), PAU_03353, PA-RVA20-21-0171 (PHOAA) Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Contractile injection systems (CISs) are cell-puncturing nanodevices that share ancestry with contractile tail bacteriophages. Photorhabdus virulence cassette (PVC) represents one group of extracellular CISs that are present in both bacteria and archaea. Here, we report the cryo-EM structure of an intact PVC from P. asymbiotica. This over 10-MDa device resembles a simplified T4 phage tail, containing a hexagonal baseplate complex with six fibers and a capped 117-nanometer sheath-tube trunk. One distinct feature of the PVC is the presence of three variants for both tube and sheath proteins, indicating a functional specialization of them during evolution. The terminal hexameric cap docks onto the topmost layer of the inner tube and locks the outer sheath in pre-contraction state with six stretching arms. Our results on the PVC provide a framework for understanding the general mechanism of widespread CISs and pave the way for using them as delivery tools in biological or therapeutic applications. Cryo-EM Structure and Assembly of an Extracellular Contractile Injection System.,Jiang F, Li N, Wang X, Cheng J, Huang Y, Yang Y, Yang J, Cai B, Wang YP, Jin Q, Gao N Cell. 2019 Apr 4;177(2):370-383.e15. doi: 10.1016/j.cell.2019.02.020. Epub 2019, Mar 21. PMID:30905475 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.