2WP9

Crystal structure of the E. coli succinate:quinone oxidoreductase (SQR) SdhB His207Thr mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Perturbation of the Quinone-Binding Site of Complex II Alters the Electronic Properties of the Proximal [3Fe-4S] Iron-Sulfur Cluster.

Ruprecht, J.Iwata, S.Rothery, R.A.Weiner, J.H.Maklashina, E.Cecchini, G.

(2011) J.Biol.Chem. 286: 12756

  • DOI: 10.1074/jbc.M110.209874

  • PubMed Abstract: 
  • Succinate-ubiquinone oxidoreductase (SQR) and menaquinol-fumarate oxidoreductase (QFR) from Escherichia coli are members of the complex II family of enzymes. SQR and QFR catalyze similar reactions with quinones; however, SQR preferentially reacts wit ...

    Succinate-ubiquinone oxidoreductase (SQR) and menaquinol-fumarate oxidoreductase (QFR) from Escherichia coli are members of the complex II family of enzymes. SQR and QFR catalyze similar reactions with quinones; however, SQR preferentially reacts with higher potential ubiquinones, and QFR preferentially reacts with lower potential naphthoquinones. Both enzymes have a single functional quinone-binding site proximal to a [3Fe-4S] iron-sulfur cluster. A difference between SQR and QFR is that the redox potential of the [3Fe-4S] cluster in SQR is 140 mV higher than that found in QFR. This may reflect the character of the different quinones with which the two enzymes preferentially react. To investigate how the environment around the [3Fe-4S] cluster affects its redox properties and catalysis with quinones, a conserved amino acid proximal to the cluster was mutated in both enzymes. It was found that substitution of SdhB His-207 by threonine (as found in QFR) resulted in a 70-mV lowering of the redox potential of the cluster as measured by EPR. The converse substitution in QFR raised the redox potential of the cluster. X-ray structural analysis suggests that placing a charged residue near the [3Fe-4S] cluster is a primary reason for the alteration in redox potential with the hydrogen bonding environment having a lesser effect. Steady state enzyme kinetic characterization of the mutant enzymes shows that the redox properties of the [3Fe-4S] cluster have only a minor effect on catalysis.


    Organizational Affiliation

    Membrane Protein Crystallography Group, Molecular Biosciences Division, Imperial College, London SW7 2AZ, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SUCCINATE DEHYDROGENASE FLAVOPROTEIN SUBUNIT
A, E, I
588Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: sdhA
EC: 1.3.5.1
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Electron Transport Chain Complexes: Complex II
Protein: 
Succinate:quinone oxidoreductase (SQR, Complex II)
Find proteins for P0AC41 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AC41
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
SUCCINATE DEHYDROGENASE IRON-SULFUR SUBUNIT
B, F, J
238Escherichia coli (strain K12)Mutation(s): 1 
Gene Names: sdhB
EC: 1.3.5.1
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Electron Transport Chain Complexes: Complex II
Protein: 
Succinate:quinone oxidoreductase (SQR, Complex II)
Find proteins for P07014 (Escherichia coli (strain K12))
Go to UniProtKB:  P07014
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
SUCCINATE DEHYDROGENASE CYTOCHROME B556 SUBUNIT
C, G, K
129Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: sdhC (cybA)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Electron Transport Chain Complexes: Complex II
Protein: 
Succinate:quinone oxidoreductase (SQR, Complex II)
Find proteins for P69054 (Escherichia coli (strain K12))
Go to UniProtKB:  P69054
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
SUCCINATE DEHYDROGENASE HYDROPHOBIC MEMBRANE ANCHOR SUBUNIT
D, H, L
115Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: sdhD
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Electron Transport Chain Complexes: Complex II
Protein: 
Succinate:quinone oxidoreductase (SQR, Complex II)
Find proteins for P0AC44 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AC44
Small Molecules
Ligands 8 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SF4
Query on SF4

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Download CCD File 
B, F, J
IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-VKOJMFJBAC
 Ligand Interaction
F3S
Query on F3S

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Download CCD File 
B, F, J
FE3-S4 CLUSTER
Fe3 S4
FCXHZBQOKRZXKS-MZMDZPPWAW
 Ligand Interaction
NA
Query on NA

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Download CCD File 
A, E, I
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
FAD
Query on FAD

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Download CCD File 
A, E, I
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
FES
Query on FES

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Download CCD File 
B, F, J
FE2/S2 (INORGANIC) CLUSTER
Fe2 S2
NIXDOXVAJZFRNF-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM

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Download CCD File 
C, G, K
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
TEO
Query on TEO

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Download CCD File 
A, E, I
MALATE LIKE INTERMEDIATE
C4 H4 O5
QFBHYOKSQPPXHZ-UWTATZPHSA-L
 Ligand Interaction
CBE
Query on CBE

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Download CCD File 
C, G, K
2-METHYL-N-PHENYL-5,6-DIHYDRO-1,4-OXATHIINE-3-CARBOXAMIDE
5,6-DIHYDRO-2-METHYL-1,4-OXATHIIN-3-CARBOXANILID; CARBOXIN; CBX
C12 H13 N O2 S
GYSSRZJIHXQEHQ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.190 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 119.853α = 90.00
b = 183.803β = 90.00
c = 202.777γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
REFMACphasing
SCALAdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-08-25
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance