2OKY

A non-invasive GFP-based biosensor for mercury ions


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.302 
  • R-Value Work: 0.225 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Design of a highly specific and noninvasive biosensor suitable for real-time in vivo imaging of mercury (II) uptake.

Chapleau, R.R.Blomberg, R.Ford, P.C.Sagermann, M.

(2008) Protein Sci. 17: 614-622

  • DOI: 10.1110/ps.073358908
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Mercury is a ubiquitous pollutant that when absorbed is extremely toxic to a wide variety of biochemical processes. Mercury (II) is a strong, "invisible" poison that is rapidly absorbed by tissues of the intestinal tract, kidneys, and liver upon inge ...

    Mercury is a ubiquitous pollutant that when absorbed is extremely toxic to a wide variety of biochemical processes. Mercury (II) is a strong, "invisible" poison that is rapidly absorbed by tissues of the intestinal tract, kidneys, and liver upon ingestion. In this study, a novel fluorescence-based biosensor is presented that allows for the direct monitoring of the uptake and distribution of the metal under noninvasive in vivo conditions. With the introduction of a cysteine residue at position 205, located in close proximity to the chromophore, the green fluorescent protein (GFP) from Aequorea victoria was converted into a highly specific biosensor for this metal ion. The mutant protein exhibits a dramatic absorbance and fluorescence change upon mercuration at neutral pH. Absorbance and fluorescence properties with respect to the metal concentration exhibit sigmoidal binding behavior with a detection limit in the low nanomolar range. Time-resolved binding studies indicate rapid subsecond binding of the metal to the protein. The crystal structures obtained of mutant eGFP205C indicate a possible access route of the metal into the core of the protein. To our knowledge, this engineered protein is a first example of a biosensor that allows for noninvasive and real-time imaging of mercury uptake in a living cell. A major advantage is that its expression can be genetically controlled in many organisms to enable unprecedented studies of tissue specific mercury uptake.


    Related Citations: 
    • Local complexity of amino acid interactions in a protein core.
      Jain, R.K.,Ranganathan, R.
      (2004) Proc.Natl.Acad.Sci.USA 101: 111
    • Crystal structure of the Aequorea victoria green fluorescent protein.
      Ormo, M.,Cubitt, A.B.,Kallio, K.,Gross, L.A.,Tsien, R.Y.,Remington, S.J.
      (1996) Science 273: 1392


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106-9510, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Green fluorescent protein
A, B
238Aequorea victoriaMutation(s): 1 
Gene Names: GFP
Find proteins for P42212 (Aequorea victoria)
Go to UniProtKB:  P42212
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CRO
Query on CRO
A, B
L-PEPTIDE LINKINGC15 H17 N3 O5THR, TYR, GLY
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.302 
  • R-Value Work: 0.225 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 87.240α = 90.00
b = 87.240β = 90.00
c = 119.090γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
ADSCdata collection
CNSrefinement
XSCALEdata scaling
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-12-04
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2018-02-14
    Type: Experimental preparation