6HS7
Type VI membrane complex
Summary for 6HS7
| Entry DOI | 10.2210/pdb6hs7/pdb |
| EMDB information | 0264 |
| Descriptor | ImcF-like family protein, Type VI secretion system protein VasD (2 entities in total) |
| Functional Keywords | membrane complex, tether, membrane protein |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 25 |
| Total formula weight | 1577252.21 |
| Authors | Rapisarda, C.,Fronzes, R. (deposition date: 2018-09-28, release date: 2019-03-27, Last modification date: 2024-05-15) |
| Primary citation | Rapisarda, C.,Cherrak, Y.,Kooger, R.,Schmidt, V.,Pellarin, R.,Logger, L.,Cascales, E.,Pilhofer, M.,Durand, E.,Fronzes, R. In situand high-resolution cryo-EM structure of a bacterial type VI secretion system membrane complex. Embo J., 38:-, 2019 Cited by PubMed Abstract: Bacteria have evolved macromolecular machineries that secrete effectors and toxins to survive and thrive in diverse environments. The type VI secretion system (T6SS) is a contractile machine that is related to phages. It is composed of a phage tail-like structure inserted in the bacterial cell envelope by a membrane complex (MC) comprising the TssJ, TssL and TssM proteins. We previously reported the low-resolution negative-stain electron microscopy structure of the enteroaggregative MC and proposed a rotational 5-fold symmetry with a TssJ:TssL:TssM stoichiometry of 2:2:2. Here, cryo-electron tomography analyses of the T6SS MC confirm the 5-fold symmetry and identify the regions of the structure that insert into the bacterial membranes. A high-resolution model obtained by single-particle cryo-electron microscopy highlights new features: five additional copies of TssJ, yielding a TssJ:TssL:TssM stoichiometry of 3:2:2, an 11-residue loop in TssM, protruding inside the lumen of the MC and constituting a functionally important periplasmic gate, and hinge regions. Based on these data, we propose an updated model on MC structure and dynamics during T6SS assembly and function. PubMed: 30877094DOI: 10.15252/embj.2018100886 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4.6 Å) |
Structure validation
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