1Y4K

Lipoxygenase-1 (Soybean) at 100K, N694G Mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Kinetic, spectroscopic, and structural investigations of the soybean lipoxygenase-1 first-coordination sphere mutant, Asn694Gly.

Segraves, E.N.Chruszcz, M.Neidig, M.L.Ruddat, V.Zhou, J.Wecksler, A.T.Minor, W.Solomon, E.I.Holman, T.R.

(2006) Biochemistry 45: 10233-10242

  • DOI: 10.1021/bi060577e

  • PubMed Abstract: 
  • In wild-type soybean LO-1 (WT sLO-1), Asn694 is a weak sixth ligand that is thought to be critical for enzymatic catalysis. In this investigation, N694G sLO-1 was studied to probe its contribution at this sixth ligand position to the kinetic and spec ...

    In wild-type soybean LO-1 (WT sLO-1), Asn694 is a weak sixth ligand that is thought to be critical for enzymatic catalysis. In this investigation, N694G sLO-1 was studied to probe its contribution at this sixth ligand position to the kinetic and spectroscopic properties. The k(cat) value of N694G is approximately 230 times lower than that of WT sLO-1 at 25 degrees C, which can be partially explained by a lowered reduction potential of the iron as seen as a shift in the visible ligand-to-metal charge-transfer band (lambda(max) = 410 nm for N694G and lambda(max) = 425 nm for WT sLO-1). This conclusion was supported by a faster rate of oxidation of N694G by the product than that of WT sLO-1 (k(2) = 606 s(-)(1) for N694G and k(2) = 349 s(-)(1) for WT sLO-1). These results suggest a stronger ligand at the active site iron than the native Asn694, which is confirmed to be a water bound to the Fe(II) in the crystal structure. This produces a six-coordinate circular dichroism/magnetic circular dichroism (CD/MCD) spectra for ferrous N694G and an intermediate rhombic electron paramagnetic resonance (EPR) signal for ferric N694G. The EPR spectrum and its pH dependence suggest that the coordination environment of ferric N694G contains one hydroxide and one water. On the basis of both kinetic and structural factors, we propose that the Asn694 water-derived ligand would likely be a hydroxide and the active site, water-derived ligand a water in the ferric state, hence lowering the reaction rate of N694G more than would be expected from the lowered reduction potential alone.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Seed lipoxygenase-1
A
839Glycine maxMutation(s): 1 
Gene Names: LOX1.1 (LOX1)
EC: 1.13.11.12
Find proteins for P08170 (Glycine max)
Go to UniProtKB:  P08170
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

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Download CCD File 
A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
EDO
Query on EDO

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Download CCD File 
A
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
FE2
Query on FE2

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Download CCD File 
A
FE (II) ION
Fe
CWYNVVGOOAEACU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.180 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 93.884α = 90.00
b = 92.835β = 90.66
c = 49.435γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-2000data collection
HKL-2000data reduction
CNSphasing
REFMACrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-12-13
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance