4MFH

Crystal Structure of M121G Azurin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.54 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.170 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Copper-sulfenate complex from oxidation of a cavity mutant of Pseudomonas aeruginosa azurin.

Sieracki, N.A.Tian, S.Hadt, R.G.Zhang, J.L.Woertink, J.S.Nilges, M.J.Sun, F.Solomon, E.I.Lu, Y.

(2014) Proc.Natl.Acad.Sci.USA 111: 924-929

  • DOI: 10.1073/pnas.1316483111

  • PubMed Abstract: 
  • Metal-sulfenate centers are known to play important roles in biology and yet only limited examples are known due to their instability and high reactivity. Herein we report a copper-sulfenate complex characterized in a protein environment, formed at t ...

    Metal-sulfenate centers are known to play important roles in biology and yet only limited examples are known due to their instability and high reactivity. Herein we report a copper-sulfenate complex characterized in a protein environment, formed at the active site of a cavity mutant of an electron transfer protein, type 1 blue copper azurin. Reaction of hydrogen peroxide with Cu(I)-M121G azurin resulted in a species with strong visible absorptions at 350 and 452 nm and a relatively low electron paramagnetic resonance gz value of 2.169 in comparison with other normal type 2 copper centers. The presence of a side-on copper-sulfenate species is supported by resonance Raman spectroscopy, electrospray mass spectrometry using isotopically enriched hydrogen peroxide, and density functional theory calculations correlated to the experimental data. In contrast, the reaction with Cu(II)-M121G or Zn(II)-M121G azurin under the same conditions did not result in Cys oxidation or copper-sulfenate formation. Structural and computational studies strongly suggest that the secondary coordination sphere noncovalent interactions are critical in stabilizing this highly reactive species, which can further react with oxygen to form a sulfinate and then a sulfonate species, as demonstrated by mass spectrometry. Engineering the electron transfer protein azurin into an active copper enzyme that forms a copper-sulfenate center and demonstrating the importance of noncovalent secondary sphere interactions in stabilizing it constitute important contributions toward the understanding of metal-sulfenate species in biological systems.


    Organizational Affiliation

    Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Azurin
A, B, C
128Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)Mutation(s): 1 
Gene Names: azu
Find proteins for P00282 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Go to UniProtKB:  P00282
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CU
Query on CU

Download SDF File 
Download CCD File 
A, B, C
COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
TRS
Query on TRS

Download SDF File 
Download CCD File 
A, B, C
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
TRIS BUFFER
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.54 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.170 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 55.747α = 90.00
b = 145.781β = 90.00
c = 97.092γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
MOLREPphasing
HKL-2000data scaling
REFMACrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2013-08-27 
  • Released Date: 2014-01-15 
  • Deposition Author(s): Tian, S., Lu, Y.

Revision History 

  • Version 1.0: 2014-01-15
    Type: Initial release
  • Version 1.1: 2014-02-05
    Type: Database references