H3BU85 · H3BU85_HUMAN
- ProteinBeta-hexosaminidase subunit alpha
- GeneHEXA
- StatusUniProtKB unreviewed (TrEMBL)
- Organism
- Amino acids360 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
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-sulfogalactosamineThis 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-galactosamineThis reaction proceeds in the forward direction.
- a ganglioside GM2 (d18:1(4E)) + H2O = a ganglioside GM3 (d18:1(4E)) + N-acetyl-beta-D-galactosamineThis reaction proceeds in the forward direction.
- a ganglioside GM2 + H2O = a ganglioside GM3 + N-acetyl-beta-D-galactosamineThis 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-galactosamineThis reaction proceeds in the forward direction.
Features
Showing features for active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Active site | 323 | Proton donor | ||||
Sequence: E |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | lysosome | |
Molecular Function | beta-N-acetylhexosaminidase activity | |
Molecular Function | N-acetyl-beta-D-galactosaminidase activity | |
Biological Process | carbohydrate derivative metabolic process | |
Biological Process | carbohydrate metabolic process | |
Biological Process | lipid metabolic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameBeta-hexosaminidase subunit alpha
- EC number
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionH3BU85
Proteomes
Organism-specific databases
Subcellular Location
PTM/Processing
Features
Showing features for signal, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-22 | |||||
Sequence: MTSSRLWFSLLLAAAFAGRATA | ||||||
Chain | PRO_5042806415 | 23-360 | Beta-hexosaminidase subunit alpha | |||
Sequence: LWPWPQNFQTSDQRYVLYPNNFQFQYDVSSAAQPGCSVLDEAFQRYRDLLFGSGSWPRPYLTGKRHTLEKNVLVVSVVTPGCNQLPTLESVENYTLTINDDQCLLLSETVWGALRGLETFSQLVWKSAEGTFFINKTEIEDFPRFPHRGLLLDTSRHYLPLSSILDTLDVMAYNKLNVFHWHLVDDPSFPYESFTFPELMRKGSYNPVTHIYTAQDVKEVIEYARLRGIRVLAEFDTPGHTLSWGPGIPGLLTPCYSGSEPSGTFGPVNPSLNNTYEFMSTFFLEVSSVFPDFYLHLGGDEVDFTCWKSNPEIQDFMRKKGFGEDFKQLESFYIQTYP |
Keywords
- PTM
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.
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 23-145 | Beta-hexosaminidase eukaryotic type N-terminal | ||||
Sequence: LWPWPQNFQTSDQRYVLYPNNFQFQYDVSSAAQPGCSVLDEAFQRYRDLLFGSGSWPRPYLTGKRHTLEKNVLVVSVVTPGCNQLPTLESVENYTLTINDDQCLLLSETVWGALRGLETFSQL | ||||||
Domain | 167-357 | Glycoside hydrolase family 20 catalytic | ||||
Sequence: FPHRGLLLDTSRHYLPLSSILDTLDVMAYNKLNVFHWHLVDDPSFPYESFTFPELMRKGSYNPVTHIYTAQDVKEVIEYARLRGIRVLAEFDTPGHTLSWGPGIPGLLTPCYSGSEPSGTFGPVNPSLNNTYEFMSTFFLEVSSVFPDFYLHLGGDEVDFTCWKSNPEIQDFMRKKGFGEDFKQLESFYIQ |
Sequence similarities
Belongs to the glycosyl hydrolase 20 family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length360
- Mass (Da)41,169
- Last updated2021-09-29 v2
- Checksum43D4CF280C59296D
Computationally mapped potential isoform sequences
There are 18 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
P06865 | HEXA_HUMAN | HEXA | 529 | ||
H3BVH8 | H3BVH8_HUMAN | HEXA | 134 | ||
H3BT62 | H3BT62_HUMAN | HEXA | 143 | ||
H3BTD4 | H3BTD4_HUMAN | HEXA | 373 | ||
H3BRP6 | H3BRP6_HUMAN | HEXA | 88 | ||
H3BS10 | H3BS10_HUMAN | HEXA | 509 | ||
H3BQ04 | H3BQ04_HUMAN | HEXA | 143 | ||
H3BP20 | H3BP20_HUMAN | HEXA | 540 | ||
A0A804HIQ5 | A0A804HIQ5_HUMAN | HEXA | 485 | ||
A0A804HJ97 | A0A804HJ97_HUMAN | HEXA | 257 | ||
A0A804HIU3 | A0A804HIU3_HUMAN | HEXA | 358 | ||
A0A804HIC7 | A0A804HIC7_HUMAN | HEXA | 121 | ||
A0A804HIC8 | A0A804HIC8_HUMAN | HEXA | 390 | ||
A0A804HLJ5 | A0A804HLJ5_HUMAN | HEXA | 474 | ||
A0A804HK32 | A0A804HK32_HUMAN | HEXA | 90 | ||
A0A804HJK0 | A0A804HJK0_HUMAN | HEXA | 96 | ||
A0A804HKX5 | A0A804HKX5_HUMAN | HEXA | 473 | ||
A0A087WTY2 | A0A087WTY2_HUMAN | HEXA | 119 |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AC009690 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
KF456090 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. |