H3BU85 · H3BU85_HUMAN

  • Protein
    Beta-hexosaminidase subunit alpha
  • Gene
    HEXA
  • Status
    UniProtKB unreviewed (TrEMBL)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    4/5

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 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. 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.

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 site323Proton donor

GO annotations

AspectTerm
Cellular Componentlysosome
Molecular Functionbeta-N-acetylhexosaminidase activity
Molecular FunctionN-acetyl-beta-D-galactosaminidase activity
Biological Processcarbohydrate derivative metabolic process
Biological Processcarbohydrate metabolic process
Biological Processlipid metabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Beta-hexosaminidase subunit alpha
  • EC number
  • Alternative names
    • Beta-N-acetylhexosaminidase subunit alpha
    • N-acetyl-beta-glucosaminidase subunit alpha

Gene names

    • Name
      HEXA

Organism names

  • Taxonomic identifier
  • Organism
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo

Accessions

  • Primary accession
    H3BU85

Proteomes

Organism-specific databases

Subcellular Location

Keywords

  • Cellular component

Disease & Variants

Genetic variation databases

PTM/Processing

Features

Showing features for signal, chain.

TypeIDPosition(s)Description
Signal1-22
ChainPRO_504280641523-360Beta-hexosaminidase subunit alpha

Keywords

Expression

Gene expression databases

Interaction

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. 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
Domain23-145Beta-hexosaminidase eukaryotic type N-terminal
Domain167-357Glycoside hydrolase family 20 catalytic

Sequence similarities

Belongs to the glycosyl hydrolase 20 family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    360
  • Mass (Da)
    41,169
  • Last updated
    2021-09-29 v2
  • Checksum
    43D4CF280C59296D
MTSSRLWFSLLLAAAFAGRATALWPWPQNFQTSDQRYVLYPNNFQFQYDVSSAAQPGCSVLDEAFQRYRDLLFGSGSWPRPYLTGKRHTLEKNVLVVSVVTPGCNQLPTLESVENYTLTINDDQCLLLSETVWGALRGLETFSQLVWKSAEGTFFINKTEIEDFPRFPHRGLLLDTSRHYLPLSSILDTLDVMAYNKLNVFHWHLVDDPSFPYESFTFPELMRKGSYNPVTHIYTAQDVKEVIEYARLRGIRVLAEFDTPGHTLSWGPGIPGLLTPCYSGSEPSGTFGPVNPSLNNTYEFMSTFFLEVSSVFPDFYLHLGGDEVDFTCWKSNPEIQDFMRKKGFGEDFKQLESFYIQTYP

Computationally mapped potential isoform sequences

There are 18 potential isoforms mapped to this entry

View all
EntryEntry nameGene nameLength
P06865HEXA_HUMANHEXA529
H3BVH8H3BVH8_HUMANHEXA134
H3BT62H3BT62_HUMANHEXA143
H3BTD4H3BTD4_HUMANHEXA373
H3BRP6H3BRP6_HUMANHEXA88
H3BS10H3BS10_HUMANHEXA509
H3BQ04H3BQ04_HUMANHEXA143
H3BP20H3BP20_HUMANHEXA540
A0A804HIQ5A0A804HIQ5_HUMANHEXA485
A0A804HJ97A0A804HJ97_HUMANHEXA257
A0A804HIU3A0A804HIU3_HUMANHEXA358
A0A804HIC7A0A804HIC7_HUMANHEXA121
A0A804HIC8A0A804HIC8_HUMANHEXA390
A0A804HLJ5A0A804HLJ5_HUMANHEXA474
A0A804HK32A0A804HK32_HUMANHEXA90
A0A804HJK0A0A804HJK0_HUMANHEXA96
A0A804HKX5A0A804HKX5_HUMANHEXA473
A0A087WTY2A0A087WTY2_HUMANHEXA119

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AC009690
EMBL· GenBank· DDBJ
-Genomic DNA No translation available.
KF456090
EMBL· GenBank· DDBJ
-Genomic DNA No translation available.

Genome annotation databases

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.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp