4YMK

Crystal Structure of Stearoyl-Coenzyme A Desaturase 1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.605 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.203 

wwPDB Validation 3D Report Full Report


This is version 1.5 of the entry. See complete history

Literature

X-ray structure of a mammalian stearoyl-CoA desaturase.

Bai, Y.McCoy, J.G.Levin, E.J.Sobrado, P.Rajashankar, K.R.Fox, B.G.Zhou, M.

(2015) Nature 524: 252-256

  • DOI: 10.1038/nature14549

  • PubMed Abstract: 
  • Stearoyl-CoA desaturase (SCD) is conserved in all eukaryotes and introduces the first double bond into saturated fatty acyl-CoAs. Because the monounsaturated products of SCD are key precursors of membrane phospholipids, cholesterol esters and triglyc ...

    Stearoyl-CoA desaturase (SCD) is conserved in all eukaryotes and introduces the first double bond into saturated fatty acyl-CoAs. Because the monounsaturated products of SCD are key precursors of membrane phospholipids, cholesterol esters and triglycerides, SCD is pivotal in fatty acid metabolism. Humans have two SCD homologues (SCD1 and SCD5), while mice have four (SCD1-SCD4). SCD1-deficient mice do not become obese or diabetic when fed a high-fat diet because of improved lipid metabolic profiles and insulin sensitivity. Thus, SCD1 is a pharmacological target in the treatment of obesity, diabetes and other metabolic diseases. SCD1 is an integral membrane protein located in the endoplasmic reticulum, and catalyses the formation of a cis-double bond between the ninth and tenth carbons of stearoyl- or palmitoyl-CoA. The reaction requires molecular oxygen, which is activated by a di-iron centre, and cytochrome b5, which regenerates the di-iron centre. To understand better the structural basis of these characteristics of SCD function, here we crystallize and solve the structure of mouse SCD1 bound to stearoyl-CoA at 2.6 Å resolution. The structure shows a novel fold comprising four transmembrane helices capped by a cytosolic domain, and a plausible pathway for lateral substrate access and product egress. The acyl chain of the bound stearoyl-CoA is enclosed in a tunnel buried in the cytosolic domain, and the geometry of the tunnel and the conformation of the bound acyl chain provide a structural basis for the regioselectivity and stereospecificity of the desaturation reaction. The dimetal centre is coordinated by a unique spacial arrangement of nine conserved histidine residues that implies a potentially novel mechanism for oxygen activation. The structure also illustrates a possible route for electron transfer from cytochrome b5 to the di-iron centre.


    Organizational Affiliation

    Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Acyl-CoA desaturase 1
A, D
339Mus musculusMutation(s): 0 
Gene Names: Scd1
EC: 1.14.19.1
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Fatty Acid Desaturases
Protein: 
Stearoyl-coenzyme A desaturase (SCD1) in complex with substrate
Find proteins for P13516 (Mus musculus)
Go to UniProtKB:  P13516
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
MPG
Query on MPG

Download SDF File 
Download CCD File 
A, D
[(Z)-octadec-9-enyl] (2R)-2,3-bis(oxidanyl)propanoate
C21 H40 O4
JPJYKWFFJCWMPK-GDCKJWNLSA-N
 Ligand Interaction
ST9
Query on ST9

Download SDF File 
Download CCD File 
A, D
STEAROYL-COENZYME A
C39 H70 N7 O17 P3 S
SIARJEKBADXQJG-LFZQUHGESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.605 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.203 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 77.061α = 90.00
b = 113.766β = 90.00
c = 141.698γ = 90.00
Software Package:
Software NamePurpose
XDSdata scaling
HKL-2000data scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
PHASERphasing
Cootmodel building
Aimlessdata scaling
SHELXDEphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited StatesR01GM098878

Revision History 

  • Version 1.0: 2015-06-24
    Type: Initial release
  • Version 1.1: 2015-07-08
    Type: Structure summary
  • Version 1.2: 2015-08-19
    Type: Database references
  • Version 1.3: 2016-06-08
    Type: Atomic model
  • Version 1.4: 2017-09-06
    Type: Author supporting evidence, Derived calculations
  • Version 1.5: 2017-11-22
    Type: Refinement description