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arylsulfatase G; ASG (ARSG, KIAA1001, UNQ839/PRO1777)
Function:
- displays arylsulfatase activity at acidic pH with pseudosubstrates, such as p-nitrocatechol sulfate & also, but with lower activity, p-nitrophenyl sulfate & 4-methylumbelliferyl sulfate
- oxidation of Cys to 3-oxoalanine seems essential for catalytic activity
Kinetic parameters:
- KM=4.2 mM for p-nitrocatechol sulfate
- Vmax=63.5 umol/min/mg enzyme toward p-nitrocatechol sulfate
- pH dependence: optimum pH is 5.4
- temperature dependence: most efficient at 45-50 degrees C
Inhibition:
- inhibited by phosphate
- the phosphate forms a covalent bond with the active site 3-oxoalanine
Cofactor: binds 1 Ca+2 per subunit (putative)
Structure:
- N-glycosylated
- belongs to the sulfatase family
Compartment: lysosome
Expression:
- widely expressed
- very low expression in brain, lung, heart & skeletal muscle
Notes:
- previously observed endoplasmic reticulum localization is most likely due to folding/maturation problems for overexpressed proteins
General
arylsulfatase
Ca+2 binding protein
glycoprotein
Properties
SIZE: entity length = 525 aa
MW = 57 kD
COMPARTMENT: lysosome
endoplasmic reticulum
MOTIF: signal sequence {1-16}
Ca+2-binding site
SITE: 44-44
Ca+2-binding site
SITE: 45-45
Ca+2-binding site
SITE: 84-84
N-glycosylation site {N117}
binding site
SITE: 137-137
FOR-BINDING-OF: Substrate
histidine residue {H139}
binding site
SITE: 162-162
FOR-BINDING-OF: Substrate
N-glycosylation site {N215}
binding site
SITE: 251-251
FOR-BINDING-OF: Substrate
Ca+2-binding site
SITE: 302-302
Ca+2-binding site
SITE: 303-303
N-glycosylation site {N356}
N-glycosylation site {N497}
Database Correlations
OMIM 610008
UniProt Q96EG1
Pfam PF00884
Entrez Gene 22901
Kegg hsa:22901
References
UniProt :accession Q96EG1