5U7Z

Human acid ceramidase (ASAH1, aCDase) self-activated


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural basis for the activation of acid ceramidase.

Gebai, A.Gorelik, A.Li, Z.Illes, K.Nagar, B.

(2018) Nat Commun 9: 1621-1621

  • DOI: 10.1038/s41467-018-03844-2
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Acid ceramidase (aCDase, ASAH1) hydrolyzes lysosomal membrane ceramide into sphingosine, the backbone of all sphingolipids, to regulate many cellular processes. Abnormal function of aCDase leads to Farber disease, spinal muscular atrophy with progres ...

    Acid ceramidase (aCDase, ASAH1) hydrolyzes lysosomal membrane ceramide into sphingosine, the backbone of all sphingolipids, to regulate many cellular processes. Abnormal function of aCDase leads to Farber disease, spinal muscular atrophy with progressive myoclonic epilepsy, and is associated with Alzheimer's, diabetes, and cancer. Here, we present crystal structures of mammalian aCDases in both proenzyme and autocleaved forms. In the proenzyme, the catalytic center is buried and protected from solvent. Autocleavage triggers a conformational change exposing a hydrophobic channel leading to the active site. Substrate modeling suggests distinct catalytic mechanisms for substrate hydrolysis versus autocleavage. A hydrophobic surface surrounding the substrate binding channel appears to be a site of membrane attachment where the enzyme accepts substrates facilitated by the accessory protein, saposin-D. Structural mapping of disease mutations reveals that most would destabilize the protein fold. These results will inform the rational design of aCDase inhibitors and recombinant aCDase for disease therapeutics.


    Organizational Affiliation

    Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, QC, H3G 0B1, Canada. bhushan.nagar@mcgill.ca.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Acid ceramidase
A, C
129Homo sapiensMutation(s): 0 
Gene Names: ASAH1ASAHHSD-33HSD33
EC: 3.5.1.23 (UniProt), 3.5.1 (UniProt)
Find proteins for Q13510 (Homo sapiens)
Go to UniProtKB:  Q13510
NIH Common Fund Data Resources
PHAROS  Q13510
Protein Feature View
  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Acid ceramidase
B, D
255Homo sapiensMutation(s): 0 
Gene Names: ASAH1ASAHHSD-33HSD33
EC: 3.5.1.23 (UniProt), 3.5.1 (UniProt)
Find proteins for Q13510 (Homo sapiens)
Go to UniProtKB:  Q13510
NIH Common Fund Data Resources
PHAROS  Q13510
Protein Feature View
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download CCD File 
B, D
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
BMA
Query on BMA

Download CCD File 
B, D
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.235 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 153.667α = 90
b = 68.312β = 120.72
c = 97.805γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2018-03-28
    Type: Initial release
  • Version 1.1: 2018-05-02
    Changes: Data collection, Database references