4QUV

Structure of an integral membrane delta(14)-sterol reductase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.743 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.233 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of an integral membrane sterol reductase from Methylomicrobium alcaliphilum.

Li, X.Roberti, R.Blobel, G.

(2015) Nature 517: 104-107

  • DOI: 10.1038/nature13797

  • PubMed Abstract: 
  • Sterols are essential biological molecules in the majority of life forms. Sterol reductases including Δ(14)-sterol reductase (C14SR, also known as TM7SF2), 7-dehydrocholesterol reductase (DHCR7) and 24-dehydrocholesterol reductase (DHCR24) reduce spe ...

    Sterols are essential biological molecules in the majority of life forms. Sterol reductases including Δ(14)-sterol reductase (C14SR, also known as TM7SF2), 7-dehydrocholesterol reductase (DHCR7) and 24-dehydrocholesterol reductase (DHCR24) reduce specific carbon-carbon double bonds of the sterol moiety using a reducing cofactor during sterol biosynthesis. Lamin B receptor (LBR), an integral inner nuclear membrane protein, also contains a functional C14SR domain. Here we report the crystal structure of a Δ(14)-sterol reductase (MaSR1) from the methanotrophic bacterium Methylomicrobium alcaliphilum 20Z (a homologue of human C14SR, LBR and DHCR7) with the cofactor NADPH. The enzyme contains ten transmembrane segments (TM1-10). Its catalytic domain comprises the carboxy-terminal half (containing TM6-10) and envelops two interconnected pockets, one of which faces the cytoplasm and houses NADPH, while the other one is accessible from the lipid bilayer. Comparison with a soluble steroid 5β-reductase structure suggests that the reducing end of NADPH meets the sterol substrate at the juncture of the two pockets. A sterol reductase activity assay proves that MaSR1 can reduce the double bond of a cholesterol biosynthetic intermediate, demonstrating functional conservation to human C14SR. Therefore, our structure as a prototype of integral membrane sterol reductases provides molecular insight into mutations in DHCR7 and LBR for inborn human diseases.


    Organizational Affiliation

    Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Delta(14)-sterol reductase
A, B
427Methylomicrobium alcaliphilum (strain DSM 19304 / NCIMB 14124 / VKM B-2133 / 20Z)Mutation(s): 0 
Gene Names: erg
EC: 1.3.1.70
Membrane protein
mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Sterol Reductases
Protein: 
Δ14 Sterol reductase
Find proteins for G4SW86 (Methylomicrobium alcaliphilum (strain DSM 19304 / NCIMB 14124 / VKM B-2133 / 20Z))
Go to UniProtKB:  G4SW86
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NDP
Query on NDP

Download SDF File 
Download CCD File 
A, B
NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.743 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.233 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 74.660α = 66.00
b = 74.615β = 90.37
c = 79.549γ = 86.86
Software Package:
Software NamePurpose
SOLVEphasing
HKL-2000data collection
HKL-2000data reduction
PHENIXrefinement
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2014-07-12 
  • Released Date: 2014-10-08 
  • Deposition Author(s): Li, X., Blobel, G.

Revision History 

  • Version 1.0: 2014-10-08
    Type: Initial release
  • Version 1.1: 2014-10-29
    Type: Database references
  • Version 1.2: 2015-01-28
    Type: Database references