1ZJL

Crystal structure of zinc-bound engineered maltose binding protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural studies of an engineered zinc biosensor reveal an unanticipated mode of zinc binding.

Telmer, P.G.Shilton, B.H.

(2005) J.Mol.Biol. 354: 829-840

  • DOI: 10.1016/j.jmb.2005.10.016
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Protein engineering was used previously to convert maltose-binding protein (MBP) into a zinc biosensor. Zn(2+) binding by the engineered MBP was thought to require a large conformational change from "open" to "closed", similar to that observed when m ...

    Protein engineering was used previously to convert maltose-binding protein (MBP) into a zinc biosensor. Zn(2+) binding by the engineered MBP was thought to require a large conformational change from "open" to "closed", similar to that observed when maltose is bound by the wild-type protein. We show that although this re-designed MBP molecule binds Zn(2+) with high affinity as previously reported, it does not adopt a closed conformation in solution as assessed by small-angle X-ray scattering. High-resolution crystallographic studies of the engineered Zn(2+)-binding MBP molecule demonstrate that Zn(2+) is coordinated by residues on the N-terminal lobe only, and therefore Zn(2+) binding does not require the protein to adopt a fully closed conformation. Additional crystallographic studies indicate that this unexpected Zn(2+) binding site can also coordinate Cu(2+) and Ni(2+) with only subtle changes in the overall conformation of the protein. This work illustrates that the energetic barrier to domain closure, which normally functions to maintain MBP in an open concentration in the absence of ligand, is not easily overcome by protein design. A comparison to the mechanism of maltose-induced domain rearrangement is discussed.


    Organizational Affiliation

    Department of Biochemistry, University of Western Ontario, London, Ontari, Canada N6A 5C1.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Maltose-binding periplasmic protein
A
370Escherichia coli (strain K12)Mutation(s): 5 
Gene Names: malE
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AEX9
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.204 
  • Space Group: P 32
Unit Cell:
Length (Å)Angle (°)
a = 80.500α = 90.00
b = 80.500β = 90.00
c = 55.900γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-12-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description