2I3C

Crystal Structure of an Aspartoacylase from Homo Sapiens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history

Re-refinement Note

A newer entry is available that reflects an alternative modeling of the original data: 2Q51


Literature

Structure of aspartoacylase, the brain enzyme impaired in Canavan disease.

Bitto, E.Bingman, C.A.Wesenberg, G.E.McCoy, J.G.Phillips, G.N.

(2007) Proc Natl Acad Sci U S A 104: 456-461

  • DOI: 10.1073/pnas.0607817104
  • Primary Citation of Related Structures:  
    2GU2, 2I3C

  • PubMed Abstract: 
  • Aspartoacylase catalyzes hydrolysis of N-acetyl-l-aspartate to aspartate and acetate in the vertebrate brain. Deficiency in this activity leads to spongiform degeneration of the white matter of the brain and is the established cause of Canavan disease, a fatal progressive leukodystrophy affecting young children ...

    Aspartoacylase catalyzes hydrolysis of N-acetyl-l-aspartate to aspartate and acetate in the vertebrate brain. Deficiency in this activity leads to spongiform degeneration of the white matter of the brain and is the established cause of Canavan disease, a fatal progressive leukodystrophy affecting young children. We present crystal structures of recombinant human and rat aspartoacylase refined to 2.8- and 1.8-A resolution, respectively. The structures revealed that the N-terminal domain of aspartoacylase adopts a protein fold similar to that of zinc-dependent hydrolases related to carboxypeptidases A. The catalytic site of aspartoacylase shows close structural similarity to those of carboxypeptidases despite only 10-13% sequence identity between these proteins. About 100 C-terminal residues of aspartoacylase form a globular domain with a two-stranded beta-sheet linker that wraps around the N-terminal domain. The long channel leading to the active site is formed by the interface of the N- and C-terminal domains. The C-terminal domain is positioned in a way that prevents productive binding of polypeptides in the active site. The structures revealed that residues 158-164 may undergo a conformational change that results in opening and partial closing of the channel entrance. We hypothesize that the catalytic mechanism of aspartoacylase is closely analogous to that of carboxypeptidases. We identify residues involved in zinc coordination, and propose which residues may be involved in substrate binding and catalysis. The structures also provide a structural framework necessary for understanding the deleterious effects of many missense mutations of human aspartoacylase.


    Organizational Affiliation

    Center for Eukaryotic Structural Genomics, University of Wisconsin, Madison, WI 53706-1544, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
AspartoacylaseA, B315Homo sapiensMutation(s): 6 
Gene Names: ASPAACY2ASP
EC: 3.5.1.15
UniProt & NIH Common Fund Data Resources
Find proteins for P45381 (Homo sapiens)
Explore P45381 
Go to UniProtKB:  P45381
PHAROS:  P45381
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 
  • Space Group: P 42 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 145.551α = 90
b = 145.551β = 90
c = 103.396γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
MOLREPphasing
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-08-29
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description