Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report

Global Symmetry: Tetrahedral - T  (3D View)
Global Stoichiometry: Homo 12-mer - A12 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 546.51 kDa 
• Atom Count: 4740 
• Modelled Residue Count: 4740 
• Deposited Residue Count: 5232 
• Unique protein chains: 1

4A8C

Symmetrized cryo-EM reconstruction of E. coli DegQ 12-mer in complex with a binding peptide

• PDB DOI: 10.2210/pdb4A8C/pdb
• EM Map EMD-1983: EMDB EMDataResource

• Classification: HYDROLASE
• Organism(s): Escherichia coli K-12
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2011-11-20 Released: 2012-01-11 
• Deposition Author(s): Malet, H., Canellas, F., Sawa, J., Yan, J., Thalassinos, K., Ehrmann, M., Clausen, T., Saibil, H.R.

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 7.50 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Newly Folded Substrates Inside the Molecular Cage of the Htra Chaperone Degq

Malet, H., Canellas, F., Sawa, J., Yan, J., Thalassinos, K., Ehrmann, M., Clausen, T., Saibil, H.R.

(2012) Nat Struct Mol Biol 19: 152

• PubMed: 22245966 
• DOI: 10.1038/nsmb.2210
• Primary Citation of Related Structures:  
  4A8A, 4A8B, 4A8C, 4A8D, 4A9G


• PubMed Abstract: 
  

The HtrA protein family combines chaperone and protease activities and is essential for protein quality control in many organisms. Whereas the mechanisms underlying the proteolytic function of HtrA proteins are well characterized, their chaperone activity remains poorly understood. Here we describe cryo-EM structures of Escherichia coli DegQ in its 12- and 24-mer states in complex with model substrates, providing a structural model of HtrA chaperone action. Up to six lysozyme substrates bind inside the DegQ 12-mer cage and are visualized in a close-to-native state. An asymmetric reconstruction reveals the binding of a well-ordered lysozyme to four DegQ protomers. DegQ PDZ domains are located adjacent to substrate density and their presence is required for chaperone activity. The substrate-interacting regions appear conserved in 12- and 24-mer cages, suggesting a common mechanism of chaperone function.

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Organizational Affiliation: 

Institute of Structural and Molecular Biology, Crystallography, Birkbeck College, London, UK.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PERIPLASMIC PH-DEPENDENT SERINE ENDOPROTEASE DEGQ	A, B, C, D, E, F, G, H, I, J, K, L	436	Escherichia coli K-12	Mutation(s): 1  Gene Names: degQ, hhoA, b3234, JW3203 EC: 3.4.21.107
UniProt
Find proteins for P39099 (Escherichia coli (strain K12)) Explore P39099  Go to UniProtKB:  P39099

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 7.50 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-11-20 
• Released Date: 2012-01-11 
Deposition Author(s): Malet, H., Canellas, F., Sawa, J., Yan, J., Thalassinos, K., Ehrmann, M., Clausen, T., Saibil, H.R.

Revision History  

• Version 1.0: 2012-01-11
  Type: Initial release
  
• Version 1.1: 2012-02-15
  Changes: Other
• Version 1.2: 2017-08-30
  Changes: Data collection, Refinement description