+Search query
-Structure paper
Title | Cryo-EM structure of a conjugative type IV secretion system suggests a molecular switch regulating pilus biogenesis. |
---|---|
Journal, issue, pages | EMBO J, Vol. 43, Issue 15, Page 3287-3306, Year 2024 |
Publish date | Jun 17, 2024 |
Authors | Kévin Macé / Gabriel Waksman / |
PubMed Abstract | Conjugative type IV secretion systems (T4SS) mediate bacterial conjugation, a process that enables the unidirectional exchange of genetic materials between a donor and a recipient bacterial cell. ...Conjugative type IV secretion systems (T4SS) mediate bacterial conjugation, a process that enables the unidirectional exchange of genetic materials between a donor and a recipient bacterial cell. Bacterial conjugation is the primary means by which antibiotic resistance genes spread among bacterial populations (Barlow 2009; Virolle et al, 2020). Conjugative T4SSs form pili: long extracellular filaments that connect with recipient cells. Previously, we solved the cryo-electron microscopy (cryo-EM) structure of a conjugative T4SS. In this article, based on additional data, we present a more complete T4SS cryo-EM structure than that published earlier. Novel structural features include details of the mismatch symmetry within the OMCC, the presence of a fourth VirB8 subunit in the asymmetric unit of both the arches and the inner membrane complex (IMC), and a hydrophobic VirB5 tip in the distal end of the stalk. Additionally, we provide previously undescribed structural insights into the protein VirB10 and identify a novel regulation mechanism of T4SS-mediated pilus biogenesis by this protein, that we believe is a key checkpoint for this process. |
External links | EMBO J / PubMed:38886579 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.46 - 6.22 Å |
Structure data | EMDB-19478: O-Layer C14 at 2.46A - Local refinement with C14 symmetry of the O-layer of the outer membrane core complex from the fully-assembled R388 type IV secretion system. EMDB-19479: I-Layer C16 at 2.69A - Local refinement with C16 symmetry of the I-layer of the outer membrane core complex from the fully-assembled R388 type IV secretion system. EMDB-19480: Conformation-A OMCC at 3.18A - Refinement without symmetry of the outer membrane core complex from the fully-assembled R388 type IV secretion system. EMDB-19481, PDB-8rt7: EMDB-19482: Conformation-C OMCC at 3.05A - Refinement without symmetry of the outer membrane core complex from the fully-assembled R388 type IV secretion system. EMDB-19483: Stalk C5 at 2.97A - Local refinement with C5 symmetry of the Stalk complex from the fully-assembled R388 type IV secretion system. EMDB-19484: Arches-protomer at 6.22A - Refinement without symmetry of the Arches-protomer complex from the fully-assembled R388 type IV secretion system. EMDB-19485: Extended inner membrne complex (IMC) protomer at 3.83A - Refinement without symmetry of the extended IMC-protomer complex from the fully-assembled R388 type IV secretion system. EMDB-19488: Stalk-Arches-IMC at 4.33A - Refinement without symmetry of the Stalk-Arches-IMC from the fully-assembled R388 type IV secretion. |
Source |
|
Keywords | MEMBRANE PROTEIN / type IV secretion system type 4 secretion system T4SS O-layer core complex outer membrane complex R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB10 VirB9 VirB7 TrwE TrwF TrwH / type IV secretion system type 4 secretion system T4SS I-layer core complex outer membrane complex R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB10 VirB9 TrwE TrwF / type IV secretion system type 4 secretion system T4SS OMCC Conformation-A core complex outer membrane complex R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB10 VirB9 VirB7 TrwE TrwF TrwH / type IV secretion system type 4 secretion system T4SS OMCC Conformation-B core complex outer membrane complex R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB10 VirB9 VirB7 TrwE TrwF TrwH / type IV secretion system type 4 secretion system T4SS OMCC Conformation-C core complex outer membrane complex R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB10 VirB9 VirB7 TrwE TrwF TrwH / type IV secretion system type 4 secretion system T4SS Stalk R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB5 VirB6 TrwI TrwJ / type IV secretion system type 4 secretion system T4SS Arches Arches-protomer R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB8 VirB10 TrwG TrwE / type IV secretion system type 4 secretion system T4SS inner membrane complex IMC IMC-protomer Extended IMC R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB3 VirB4 VirB6 VirB8 VirB10 TrwM TrwK TrwI TrwG TrwE / type IV secretion system type 4 secretion system T4SS Arches Stalk inner membrane complex IMC R388 plasmid conjugation bacterial secretion secretion secretion system protein complex VirB3 VirB4 VirB5 VirB6 VirB8 VirB10 TrwM TrwK TrwJ TrwI TrwG TrwE |