3OPO

Crystal structure of the membrane fusion protein CusB from Escherichia coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.85 Å
  • R-Value Free: 0.340 
  • R-Value Work: 0.295 
  • R-Value Observed: 0.297 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Crystal structure of the membrane fusion protein CusB from Escherichia coli.

Su, C.C.Yang, F.Long, F.Reyon, D.Routh, M.D.Kuo, D.W.Mokhtari, A.K.Van Ornam, J.D.Rabe, K.L.Hoy, J.A.Lee, Y.J.Rajashankar, K.R.Yu, E.W.

(2009) J Mol Biol 393: 342-355

  • DOI: 10.1016/j.jmb.2009.08.029
  • Primary Citation of Related Structures:  
    3H94, 3OOC, 3OPO, 3OW7

  • PubMed Abstract: 
  • Gram-negative bacteria, such as Escherichia coli, frequently utilize tripartite efflux complexes belonging to the resistance-nodulation-division family to expel diverse toxic compounds from the cell. These systems contain a periplasmic membrane fusion protein (MFP) that is critical for substrate transport ...

    Gram-negative bacteria, such as Escherichia coli, frequently utilize tripartite efflux complexes belonging to the resistance-nodulation-division family to expel diverse toxic compounds from the cell. These systems contain a periplasmic membrane fusion protein (MFP) that is critical for substrate transport. We here present the x-ray structures of the CusB MFP from the copper/silver efflux system of E. coli. This is the first structure of any MFPs associated with heavy-metal efflux transporters. CusB bridges the inner-membrane efflux pump CusA and outer-membrane channel CusC to mediate resistance to Cu(+) and Ag(+) ions. Two distinct structures of the elongated molecules of CusB were found in the asymmetric unit of a single crystal, which suggests the flexible nature of this protein. Each protomer of CusB can be divided into four different domains, whereby the first three domains are mostly beta-strands and the last domain adopts an entirely helical architecture. Unlike other known structures of MFPs, the alpha-helical domain of CusB is folded into a three-helix bundle. This three-helix bundle presumably interacts with the periplasmic domain of CusC. The N- and C-termini of CusB form the first beta-strand domain, which is found to interact with the periplasmic domain of the CusA efflux pump. Atomic details of how this efflux protein binds Cu(+) and Ag(+) were revealed by the crystals of the CusB-Cu(I) and CusB-Ag(I) complexes. The structures indicate that CusB consists of multiple binding sites for these metal ions. These findings reveal novel structural features of an MFP in the resistance-nodulation-division efflux system and provide direct evidence that this protein specifically interacts with transported substrates.


    Organizational Affiliation

    Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, 50011, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cation efflux system protein cusBA, B413Escherichia coli K-12Mutation(s): 0 
Gene Names: cusBylcDb0574JW0563
Membrane protein
Mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Multi-Drug Efflux Transporters
Protein: 
CusB membrane fusion protein (apo protein)
Find proteins for P77239 (Escherichia coli (strain K12))
Explore P77239 
Go to UniProtKB:  P77239
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
AG
Query on AG

Download Ideal Coordinates CCD File 
C [auth A], D [auth B]SILVER ION
Ag
FOIXSVOLVBLSDH-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.85 Å
  • R-Value Free: 0.340 
  • R-Value Work: 0.295 
  • R-Value Observed: 0.297 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 84.803α = 90
b = 114.678β = 90
c = 259.166γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
ADSCdata collection
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2010-09-01 
  • Released Date: 2011-04-27 
  • Deposition Author(s): Su, C.-C.

Revision History  (Full details and data files)

  • Version 1.0: 2011-04-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance