2B1K

Crystal structure of E. coli CcmG protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structures of E. coli CcmG and its mutants reveal key roles of the N-terminal beta-sheet and the fingerprint region

Ouyang, N.Gao, Y.G.Hu, H.Y.Xia, Z.X.

(2006) Proteins 65: 1021-1031

  • DOI: 10.1002/prot.21184
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • CcmG, also designated DsbE, functions as a periplasmic protein thiol:disulfide oxidoreductase and is required for cytochrome c maturation. Here we report the crystal structures of Escherichia coli CcmG and its two mutants, P144A and the N-terminal fi ...

    CcmG, also designated DsbE, functions as a periplasmic protein thiol:disulfide oxidoreductase and is required for cytochrome c maturation. Here we report the crystal structures of Escherichia coli CcmG and its two mutants, P144A and the N-terminal fifty seven-residue deletion mutant, and two additional deletion mutants were studied by circular dichroism. Structural comparison of E. coli CcmG with its deletion mutants reveals that the N-terminal beta-sheet is essential for maintaining the folding topology and consequently maintaining the active-site structure of CcmG. Pro144 and Glu145 are key residues of the fingerprint region of CcmG. Pro144 is in cis-configuration, and it makes van der Waals interactions with the active-site disulfide Cys80-Cys83 and forms a C--H...O hydrogen bond with Thr82, helping stabilize the active-site structure. Glu145 forms a salt-bridge and hydrogen-bond network with other residues of the fingerprint region and with Arg158, further stabilizing the active-site structure. The cis-configuration of Pro144 makes the backbone nitrogen and oxygen of Ala143 exposed to solvent, favorable for interacting with binding partners. The key role of cis-Pro144 is verified by the P144A mutant, which contains trans-Ala144 and displays redox property changes. Structural comparison of E. coli CcmG with the recently reported structure of CcmG in complex with the N-terminal domain of DsbD reveals that Tyr141 undergoes conformational changes upon binding DsbD. A cis-proline located at the N-terminus of the first beta-strand of the betabetaalpha motif of the thioredoxin-like domain is a conserved structural feature of the thioredoxin superfamily.


    Organizational Affiliation

    State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Thiol:disulfide interchange protein dsbE
A
168Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: dsbE (ccmG, yejQ)
Find proteins for P0AA86 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AA86
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.190 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 35.483α = 90.00
b = 48.515β = 90.00
c = 84.775γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
CNSrefinement
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-09-05
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance