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bifunctional heparan sulfate N-deacetylase/N-sulfotransferase 4; glucosaminyl N-deacetylase/N-sulfotransferase 4; NDST-4; N-heparan sulfate sulfotransferase 4; N-HSST 4; includes: heparan sulfate N-deacetylase 4; heparan sulfate N-sulfotransferase 4 (NDST4, HSST4)
Function:
1) bifunctional enzyme in heparin/heparan sulfate synthesis
2) catalyzes both N-deacetylation & N-sulfation of glucosamine of glycosaminoglycan in heparan sulfate.
3) modifies GlcNAc-GlcA dissacharide repeating sugar backbone to make N-sulfated heparosan, substrate for later modifications in heparin biosynthesis
4) high deacetylase activity but low sulfotransferase activity
3'-phosphoadenylyl sulfate + [heparan sulfate]-glucosamine
adenosine 3',5'-bisphosphate +
[heparan sulfate]-N-sulfoglucosamin
Structure:
- monomer
- belongs to the sulfotransferase 1 family, NDST subfamily
Compartment: Golgi apparatus
Comparative biology:
- presence of 4 different heparan sulfate N-deacetylase/ N-sulfotransferase enzymes in mammals, & differences in enzyme activity suggest that some initiate heparan sulfate modification/sulfation reactions, whereas others extend already modified heparan sulfate sequences
General
glycoprotein
hydrolase
sulfotransferase
Properties
SIZE: entity length = 872 aa
MW = 101 kD
COMPARTMENT: golgi
MOTIF: transmembrane domain {14-34}
Heparan sulfate N-deacetylase 4 {36-588}
MOTIF: N-glycosylation site {N226}
N-glycosylation site {N341}
N-glycosylation site {N391}
Heparan sulfate N-sulfotransferase 4 {589-872}
MOTIF: lysine residue {K604}
N-glycosylation site {N657}
binding site
SITE: 702-702
FOR-BINDING-OF: 3'-phosphoadenosine-5'-phosphosulfate
N-glycosylation site {N793}
cysteine residue {C808}
MODIFICATION: cysteine residue {C818}
cysteine residue {C818}
MODIFICATION: cysteine residue {C808}
Database Correlations
UniProt Q9H3R1
PFAM correlations
Entrez Gene 64579
Kegg hsa:64579
ENZYME 2.8.2.8
References
- UniProt :accession Q9H3R1
- GGDB; Note: glycogene database
http://riodb.ibase.aist.go.jp/rcmg/ggdb/