+Search query
-Structure paper
Title | Cryo-EM structure of the bifunctional secretin complex of . |
---|---|
Journal, issue, pages | Elife, Vol. 6, Year 2017 |
Publish date | Dec 27, 2017 |
Authors | Edoardo D'Imprima / Ralf Salzer / Ramachandra M Bhaskara / Ricardo Sánchez / Ilona Rose / Lennart Kirchner / Gerhard Hummer / Werner Kühlbrandt / Janet Vonck / Beate Averhoff / |
PubMed Abstract | Secretins form multimeric channels across the outer membrane of Gram-negative bacteria that mediate the import or export of substrates and/or extrusion of type IV pili. The secretin complex of is an ...Secretins form multimeric channels across the outer membrane of Gram-negative bacteria that mediate the import or export of substrates and/or extrusion of type IV pili. The secretin complex of is an oligomer of the 757-residue PilQ protein, essential for DNA uptake and pilus extrusion. Here, we present the cryo-EM structure of this bifunctional complex at a resolution of ~7 Å using a new reconstruction protocol. Thirteen protomers form a large periplasmic domain of six stacked rings and a secretin domain in the outer membrane. A homology model of the PilQ protein was fitted into the cryo-EM map. A crown-like structure outside the outer membrane capping the secretin was found not to be part of PilQ. Mutations in the secretin domain disrupted the crown and abolished DNA uptake, suggesting a central role of the crown in natural transformation. |
External links | Elife / PubMed:29280731 / PubMed Central |
Methods | EM (single particle) |
Resolution | 6.5 - 20.4 Å |
Structure data | EMDB-3985: EMDB-3995: EMDB-3996: EMDB-3997: EMDB-3998: |
Source |
|