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A0A218V9R7 · A0A218V9R7_9PASE

Function

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. The isozyme B does not hydrolyze each of these substrates, however hydrolyzes efficiently neutral oligosaccharide. Only the isozyme A is responsible for the degradation of GM2 gangliosides in the presence of GM2A. During fertilization is responsible, at least in part, for the zona block to polyspermy. Present in the cortical granules of non-activated oocytes, is exocytosed during the cortical reaction in response to oocyte activation and inactivates the sperm galactosyltransferase-binding site, accounting for the block in sperm binding to the zona pellucida.

Caution

The sequence shown here is derived from an EMBL/GenBank/DDBJ whole genome shotgun (WGS) entry which is preliminary data.

Catalytic 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-sulfogalactosamine
    This reaction proceeds in the forward direction.
  • 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-galactosamine
    This reaction proceeds in the forward direction.
  • Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides.
    EC:3.2.1.52 (UniProtKB | ENZYME | Rhea)
  • a ganglioside GM2 (d18:1(4E)) + H2O = a ganglioside GM3 (d18:1(4E)) + N-acetyl-beta-D-galactosamine
    This reaction proceeds in the forward direction.
  • a ganglioside GM2 + H2O = a ganglioside GM3 + N-acetyl-beta-D-galactosamine
    This reaction proceeds in the forward direction.
  • 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-galactosamine
    This reaction proceeds in the forward direction.

Features

Showing features for active site.

TypeIDPosition(s)Description
Active site390Proton donor

GO annotations

AspectTerm
Cellular Componentcortical granule
Cellular Componentlysosome
Cellular Componentmembrane
Molecular Functionbeta-N-acetylhexosaminidase activity
Molecular FunctionN-acetyl-beta-D-galactosaminidase activity
Biological Processcarbohydrate metabolic process
Biological Processganglioside catabolic process
Biological Processglycosaminoglycan metabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Beta-hexosaminidase
  • EC number

Gene names

    • Name
      HEXB
    • ORF names
      RLOC_00008155

Organism names

  • Taxonomic identifier
  • Strain
    • White83orange57
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Archelosauria > Archosauria > Dinosauria > Saurischia > Theropoda > Coelurosauria > Aves > Neognathae > Neoaves > Telluraves > Australaves > Passeriformes > Passeroidea > Estrildidae > Estrildinae > Lonchura

Accessions

  • Primary accession
    A0A218V9R7

Proteomes

Subcellular Location

Keywords

PTM/Processing

Features

Showing features for signal, chain, disulfide bond.

Type
IDPosition(s)Description
Signal1-31
ChainPRO_501337011232-593Beta-hexosaminidase
Disulfide bond85↔135
Disulfide bond344↔395
Disulfide bond569↔586

Keywords

Interaction

Subunit

There are 3 forms of beta-hexosaminidase: hexosaminidase A is a heterodimer composed of one subunit alpha and one subunit beta (chain A and B); hexosaminidase B is a homodimer of two beta subunits (two chains A and B); hexosaminidase S is a homodimer of two alpha subunits. The composition of the dimer (isozyme A versus isozyme S) has a significant effect on the substrate specificity of the alpha subunit active site.

Protein-protein interaction databases

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain50-213Beta-hexosaminidase eukaryotic type N-terminal
Domain235-551Glycoside hydrolase family 20 catalytic

Sequence similarities

Belongs to the glycosyl hydrolase 20 family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    593
  • Mass (Da)
    66,578
  • Last updated
    2017-09-27 v1
  • MD5 Checksum
    03516EC65F589DCB065B7A7EBAB5350E
MGLAGLLLGLVAVPAVLVSTSLRRGAPRAEAEPEPSGWELAADALPEDSLWPLPQRVRTSPRRLQLAPSRFQLVHGAGSSAGPGCGLLQDAFRRYYEYMFGHSRWRAWGRGPLAARAEPELLQLQVVIEAGDPGCDGHPRLASSEACEYRPAASSGRRCALAFPSRAQVCGGAHHLTVTEPVAILKASEVWGALRVEIPFLDIFPGLETFSQLVHEDDYGSFLVNESEINDFPRFAHRGVLLDTSRHYLPLKSILTNLDAMAFNKFNVLHWHIVDDQSFPYQSIYFPELSDKGAYSSNLIYTPTDVRLVIEYARLRGIRVIPEFDTPGHTQSWGKGQKDLLTPCYNRGQPTGSFGPVNPVWNTTYNFMTKFFKEISSVFPDEFIHLGGDEVDFSCWKSNPEVKEFMKKQGFGIDYAKLESYYVQNILEIVSSYNKGQMVWQEVFDHKAQLKPDTVVQVWMANNYASELSRVTRAGFTAVLSAPWYLDYISYGQDWKKYYSVEPLNFPGSEEQKKLLIGGEACLWGEFVDATNLTPRLWPRASAVGERLWSSSNVTNLQDAYKRLTSHRCRMLRRGIAAEPVFVGYCAHEARGP

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
MUZQ01000022
EMBL· GenBank· DDBJ
OWK62797.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
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