4PTZ

Crystal structure of the Escherichia coli alkanesulfonate FMN reductase SsuE in FMN-bound form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.175 

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Literature

Crystal Structure of Escherichia coli SsuE: Defining a General Catalytic Cycle for FMN Reductases of the Flavodoxin-like Superfamily.

Driggers, C.M.Dayal, P.V.Ellis, H.R.Karplus, P.A.

(2014) Biochemistry 53: 3509-3519

  • DOI: 10.1021/bi500314f
  • Primary Citation of Related Structures:  
    4PU0, 4PTY, 4PTZ

  • PubMed Abstract: 
  • The Escherichia coli sulfur starvation utilization (ssu) operon includes a two-component monooxygenase system consisting of a nicotinamide adenine dinucleotide phosphate (NADPH)-dependent flavin mononucleotide (FMN) reductase, SsuE, and a monooxygenase, SsuD ...

    The Escherichia coli sulfur starvation utilization (ssu) operon includes a two-component monooxygenase system consisting of a nicotinamide adenine dinucleotide phosphate (NADPH)-dependent flavin mononucleotide (FMN) reductase, SsuE, and a monooxygenase, SsuD. SsuE is part of the flavodoxin-like superfamily, and we report here the crystal structures of its apo, FMN-bound, and FMNH2-bound forms at ∼2 Å resolution. In the crystals, SsuE forms a tetramer that is a dimer of dimers similar to those seen for homologous FMN reductases, quinone reductases, and the WrbA family of enzymes. A π-helix present at the tetramer building interface is unique to the reductases from two-component monooxygenase systems. Analytical ultracentrifugation studies of SsuE confirm a dimer-tetramer equilibrium exists in solution, with FMN binding favoring the dimer. As the active site includes residues from both subunits, at least a dimeric association is required for the function of SsuE. The structures show that one FMN binds tightly in a deeply held site, which makes available a second binding site, in which either a second FMN or the nicotinamide of NADPH can bind. The FMNH2-bound structure shows subtle changes consistent with its binding being weaker than that of FMN. Combining this information with published kinetic studies, we propose a general catalytic cycle for two-component reductases of the flavodoxin-like superfamily, by which the enzyme can potentially provide FMNH2 to its partner monooxygenase by different routes depending on the FMN concentration and the presence of a partner monooxygenase.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, Oregon State University , 2011 Agricultural and Life Sciences Building, Corvallis, Oregon 97331, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
FMN reductase SsuEB [auth A], C [auth B], A [auth C], D191Escherichia coli K-12Mutation(s): 0 
Gene Names: ssuEycbPb0937JW0920
EC: 1.5.1.38
Find proteins for P80644 (Escherichia coli (strain K12))
Explore P80644 
Go to UniProtKB:  P80644
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMN
Query on FMN

Download Ideal Coordinates CCD File 
E [auth C], F [auth C], H [auth A], I [auth A], L [auth B], M [auth B], Q [auth D]FLAVIN MONONUCLEOTIDE
C17 H21 N4 O9 P
FVTCRASFADXXNN-SCRDCRAPSA-N
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
K [auth A]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
G [auth C], J [auth A], N [auth B], O [auth B], P [auth B], R [auth D], S [auth D], T [auth D]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.175 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 186.746α = 90
b = 186.746β = 90
c = 93.371γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
PHASERphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-06-18
    Type: Initial release