chain
-
signal peptide:1-22
-
propeptide:23-88
-
chain:89-529
checksum
DACB3E3992E57A47
comment
-
FUNCTION Hydrolyzes the non-reducing end N-acetyl-D-hexosamine and/or sulfated N-acetyl-D-hexosamine of glycoconjugates, such as the oligosaccharide moieties from proteins and neutral glycolipids, or from certain mucopolysaccharides (PubMed:11707436, PubMed:8123671, PubMed:8672428, PubMed:9694901). The isozyme S is as active as the isozyme A on the anionic bis-sulfated glycans, the chondroitin-6-sulfate trisaccharide (C6S-3), and the dermatan sulfate pentasaccharide, and the sulfated glycosphingolipid SM2 (PubMed:11707436). The isozyme B does not hydrolyze each of these substrates, however hydrolyzes efficiently neutral oligosaccharide (PubMed:11707436). Only the isozyme A is responsible for the degradation of GM2 gangliosides in the presence of GM2A (PubMed:8123671, PubMed:8672428, PubMed:9694901).CATALYTIC ACTIVITY Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides.CATALYTIC ACTIVITY N-acetyl-beta-D-galactosaminyl-(1->4)-beta-D-3-sulfogalactosyl-(1->4)-beta-D-glucosyl-(1<->1')-ceramide + H2O = a beta-D-3-sulfogalactosyl-(1->4)-beta-D-glucosyl-(1<->1')-ceramide + N-acetyl-beta-D-galactosamineCATALYTIC ACTIVITY a ganglioside GM2 (d18:1(4E)) + H2O = a ganglioside GM3 (d18:1(4E)) + N-acetyl-beta-D-galactosamineCATALYTIC ACTIVITY a ganglioside GM2 + H2O = a ganglioside GM3 + N-acetyl-beta-D-galactosamineCATALYTIC ACTIVITY beta-D-GalNAc-(1->4)-alpha-L-IdoA-(1->3)-beta-D-GalNAc-4-sulfate-(1->4)-alpha-L-IdoA-(1->3)-D-GalNAc-4-sulfate + H2O = alpha-L-IdoA-(1->3)-beta-D-GalNAc-4-sulfate-(1->4)-alpha-L-IdoA-(1->3)-D-GalNAc-4-sulfate + N-acetyl-D-galactosamineCATALYTIC ACTIVITY N-acetyl-beta-D-6-sulfogalactosaminyl-(1->4)-alpha-L-iduronyl-(1->3)-N-acetyl-D-6-sulfogalactosamine + H2O = alpha-L-iduronyl-(1->3)-N-acetyl-D-6-sulfogalactosamine + N-acetyl-D-6-sulfogalactosamineACTIVITY REGULATION Addition of GM2A stimulates the hydrolysis of sulfated glycosphingolipid SM2 and the ganglioside GM2.SUBUNIT There are 3 beta-hexosaminidase isozymes: isozyme A (hexosaminidase A) is a heterodimer composed of one subunit alpha and one subunit beta (chain A and B); isozyme B (hexosaminidase B) is a homodimer of two beta subunits (two chains A and B); isozyme S (hexosaminidase S) is a homodimer of two alpha subunits (PubMed:16698036). The composition of the dimer (isozyme A versus isozyme S) has a significant effect on the substrate specificity of the alpha subunit active site (PubMed:8672428).INTERACTION N-linked glycan at Asn-115 consists of Man(3)-GlcNAc(2) (Probable) (PubMed:1533633, PubMed:16698036, PubMed:19159218). N-linked glycan at Asn-157 consists of either GlcNAc or GlcNAc(2)-Man(7-9). N-linked glycan at Asn-295 consists of either GlcNAc, GlcNAc-Fuc, or GlcNAc(2)-Man(4) (Probable).DISEASE The disease is caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the glycosyl hydrolase 20 family.
databaseName
UniProt
dbId
56472
description
-
recommendedName: fullName evidence="46"Beta-hexosaminidase subunit alpha ecNumber evidence="1 30 34 43"3.2.1.52 alternativeName: Beta-N-acetylhexosaminidase subunit alpha shortName: Hexosaminidase subunit A alternativeName: N-acetyl-beta-glucosaminidase subunit alpha
displayName
UniProt:P06865 HEXA
identifier
P06865
isSequenceChanged
false
keyword
-
3D-structure
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Alternative splicing
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Direct protein sequencing
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Disease variant
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Disulfide bond
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Gangliosidosis
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Glycoprotein
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Glycosidase
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Hydrolase
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Lipid metabolism
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Lysosome
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Neurodegeneration
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Proteomics identification
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Reference proteome
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Signal
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Zymogen
moleculeType
Protein
schemaClass
ReferenceGeneProduct
secondaryIdentifier
-
HEXA_HUMAN
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B4DKE7
-
E7ENH7
-
Q53HS8
-
Q6AI32
sequenceLength
529
stId
uniprot:P06865