3X2R

Structure of the nonameric bacterial amyloid secretion channel CsgG


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.244 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Structure of the nonameric bacterial amyloid secretion channel

Cao, B.Zhao, Y.Kou, Y.Ni, D.Zhang, X.C.Huang, Y.

(2014) Proc.Natl.Acad.Sci.USA 111: E5439-E5444

  • DOI: 10.1073/pnas.1411942111
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Various strains of bacteria are able to produce a unique class of functional amyloids termed curli, which are critical for biofilm formation, host cell adhesion, and colonization of inert surfaces. Curli are secreted via the type VIII bacterial secre ...

    Various strains of bacteria are able to produce a unique class of functional amyloids termed curli, which are critical for biofilm formation, host cell adhesion, and colonization of inert surfaces. Curli are secreted via the type VIII bacterial secretion system, and they share biochemical and structural characteristics with amyloid fibers that have been implicated in deleterious disease in humans. Here, we report the crystal structure of Escherichia coli CsgG, which is an essential lipoprotein component of the type VIII secretion system and which forms a secretion channel in the bacterial outer membrane for transporting curli subunits. CsgG forms a crown-shaped, symmetric nonameric channel that spans the outer membrane via a 36-strand β-barrel, with each subunit contributing four β-strands. This nonameric complex contains a central channel with a pore located at the middle. The eyelet of the pore is ∼12 Å in diameter and is lined with three stacked nine-residue rings consisting of Tyr-66, Asn-70, or Phe-71. Our structure-based functional studies suggest that Tyr-66 and Phe-71 residues function as gatekeepers for the selective secretion of curli subunits. Our study describes in detail, to our knowledge, the first core structure of the type VIII bacterial secretion machinery. Importantly, our structural analysis suggests that the curli subunits are secreted via CsgG across the bacterial outer membrane in an unfolded form.


    Organizational Affiliation

    National Laboratory of Biomacromolecules, National Center of Protein Science-Beijing, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; School of Life Sciences, University of Science and Technology of China, Hefei 230027, Anhui, China; and.,National Laboratory of Biomacromolecules, National Center of Protein Science-Beijing, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China;,National Laboratory of Biomacromolecules, National Center of Protein Science-Beijing, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; yihuahuang@sun5.ibp.ac.cn.,National Laboratory of Biomacromolecules, National Center of Protein Science-Beijing, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100101, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CsgG
D, A, B, C, E, F, G, H, I
277Escherichia coli Xuzhou21Mutation(s): 0 
Gene Names: CDCO157_1350
Find proteins for A0A0F6C2F5 (Escherichia coli Xuzhou21)
Go to UniProtKB:  A0A0F6C2F5
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.244 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 171.877α = 90.00
b = 176.715β = 90.00
c = 103.524γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHENIXrefinement
SOLVEphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-01-21
    Type: Initial release