A0A2I0U9D6 · A0A2I0U9D6_LIMLA

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.

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 site355Proton 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

    • ORF names
      llap_7024

Organism names

  • Taxonomic identifier
  • Organism
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Archelosauria > Archosauria > Dinosauria > Saurischia > Theropoda > Coelurosauria > Aves > Neognathae > Neoaves > Charadriiformes > Scolopacidae > Limosa

Accessions

  • Primary accession
    A0A2I0U9D6

Proteomes

Subcellular Location

Keywords

PTM/Processing

Features

Showing features for signal, chain, disulfide bond.

Type
IDPosition(s)Description
Signal1-18
ChainPRO_501419049919-558Beta-hexosaminidase
Disulfide bond87↔137
Disulfide bond309↔360
Disulfide bond534↔551

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.

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain52-178Beta-hexosaminidase eukaryotic type N-terminal
Domain200-516Glycoside hydrolase family 20 catalytic

Sequence similarities

Belongs to the glycosyl hydrolase 20 family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    558
  • Mass (Da)
    62,896
  • Last updated
    2018-02-28 v1
  • Checksum
    DDC3972197437471
MGLAGLLLGLFLVPAVLVSTSLRHGVPPTEPEAPPELAEWESVSGTVREDSLWPLPQWLRTSRRQLQLAPGRFQLVHGAGSSAGPGCGLLQDAFRRYYEYMFGQSRGRTWGRGPPGGLGGPELLELQVVIEAPDPGCNSYPHLASSEAYHLTVTEPVAILKADEVWGALRGLETFSQLVHEDDYGSFLVNESEIDDFPRFAHRGILLDTSRHYLPLKSILTNLDAMAFNKFNVLHWHIVDDQSFPYQSIYFPELSDKGAYSYNHIYTPTDVRLVIEYARLRGIRVIPEFDTPGHTQSWGKGQKDLLTPCYSGKHPTGSFGPVNPILNTTYDFMTKFYKEISNVFPDAYIHLGGDEVDFNCWKSNPDVREFMKQQGFGIDYAKLESYYIQKILDIVSSNNKGYVVWQEVFDNKAQLKPDTVVQVWIGNNYAHELSSVTGAGFTAILSAPWYLDYISYGQDWKKYYSVEPLNFPGSEKQKKLLIGGEACLWGEFVDATNLTPRLWPRASAVGERLWSSRNVTNLQDAYERLTNHRCRMLRRGIAAEPVFTGYCAHEARGQ

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
KZ505970
EMBL· GenBank· DDBJ
PKU42669.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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