PDBsum entry: 1e33

Hydrolase

PDB id: 1e33

Contents

Protein chain

481 a.a. *

Ligands

NDG-NDG

Metals

_MG

Waters ×170

* Residue conservation analysis

PDB id:

1e33

Name:

Hydrolase

Title:

Crystal structure of an arylsulfatase a mutant p426l

Structure:

Arylsulfatase a. Chain: p. Synonym: cerebroside-3-sulfate-sulfatase. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Organ: testis. Cellular_location: lysosome. Plasmid: pmpsveh. Gene: arsa

Biol. unit:

Homo-Dimer (from PDB file)

Resolution:

2.50Å R-factor: 0.187 R-free: 0.250

Authors:

R.Von Buelow,B.Schmidt,T.Dierks,K.Von Figura,I.Uson

Key ref:

R.von Bülow et al. (2002). Defective oligomerization of arylsulfatase a as a cause of its instability in lysosomes and metachromatic leukodystrophy. J Biol Chem, 277, 9455-9461. PubMed id: 11777924 DOI: 10.1074/jbc.M111993200

Date:

06-Jun-00 Release date: 25-May-01

Protein chain

P15289  (ARSA_HUMAN) -  Arylsulfatase A

Seq: 507 a.a.

Struc: 481 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.1.6.8 - Cerebroside-sulfatase.
• Reaction: A cerebroside 3-sulfate + H₂O = a cerebroside + sulfate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

 Gene Ontology (GO) functional annotation 

• Cellular component: plasma membrane (3 terms)
• Biological process: metabolic process (2 terms)
• Biochemical function: catalytic activity (7 terms)

reference

DOI no: 10.1074/jbc.M111993200

J Biol Chem 277:9455-9461 (2002)

PubMed id: 11777924

Defective oligomerization of arylsulfatase a as a cause of its instability in lysosomes and metachromatic leukodystrophy.

R.von Bülow, B.Schmidt, T.Dierks, N.Schwabauer, K.Schilling, E.Weber, I.Usón, K.von Figura.

ABSTRACT

In one of the most common mutations causing metachromatic leukodystrophy, the P426L-allele of arylsulfatase A (ASA), the deficiency of ASA results from its instability in lysosomes. Inhibition of lysosomal cysteine proteinases protects the P426L-ASA and restores the sulfatide catabolism in fibroblasts of the patients. P426L-ASA, but not wild type ASA, was cleaved by purified cathepsin L at threonine 421 yielding 54- and 9-kDa fragments. X-ray crystallography at 2.5-A resolution showed that cleavage is not due to a difference in the protein fold that would expose the peptide bond following threonine 421 to proteases. Octamerization, which depends on protonation of Glu-424, was impaired for P426L-ASA. The mutation lowers the pH for the octamer/dimer equilibrium by 0.6 pH units from pH 5.8 to 5.2. A second oligomerization mutant (ASA-A464R) was generated that failed to octamerize even at pH 4.8. A464R-ASA was degraded in lysosomes to catalytically active 54-kDa intermediate. In cathepsin L-deficient fibroblasts, degradation of P426L-ASA and A464R-ASA to the 54-kDa fragment was reduced, while further degradation was blocked. This indicates that defective oligomerization of ASA allows degradation of ASA to a catalytically active 54-kDa intermediate by lysosomal cysteine proteinases, including cathepsin L. Further degradation of the 54-kDa intermediate critically depends on cathepsin L and is modified by the structure of the 9-kDa cleavage product.