From Wikipedia, the free encyclopedia
Jump to: navigation, search
Hexosaminidase B (beta polypeptide)
Protein HEXB PDB 1nou.png
PDB rendering based on 1nou.
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols HEXB ; ENC-1AS; HEL-248
External IDs OMIM606873 MGI96074 HomoloGene437 ChEMBL: 5877 GeneCards: HEXB Gene
EC number
RNA expression pattern
PBB GE HEXB 201944 at tn.png
More reference expression data
Species Human Mouse
Entrez 3074 15212
Ensembl ENSG00000049860 ENSMUSG00000021665
UniProt P07686 P20060
RefSeq (mRNA) NM_000521 NM_010422
RefSeq (protein) NP_000512 NP_034552
Location (UCSC) Chr 5:
74.64 – 74.72 Mb
Chr 13:
97.18 – 97.2 Mb
PubMed search [1] [2]

Beta-hexosaminidase subunit beta is an enzyme that in humans is encoded by the HEXB gene.[1][2][3]

Hexosaminidase B is the beta subunit of the lysosomal enzyme beta-hexosaminidase that, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Beta-hexosaminidase is composed of two subunits, alpha and beta, which are encoded by separate genes. Both beta-hexosaminidase alpha and beta subunits are members of family 20 of glycosyl hydrolases. Mutations in the alpha or beta subunit genes lead to an accumulation of GM2 ganglioside in neurons and neurodegenerative disorders termed the GM2 gangliosidoses. Beta subunit gene mutations lead to Sandhoff disease (GM2-gangliosidosis type II).[3]


  1. ^ O'Dowd BF, Quan F, Willard HF, Lamhonwah AM, Korneluk RG, Lowden JA, Gravel RA, Mahuran DJ (Apr 1985). "Isolation of cDNA clones coding for the beta subunit of human beta-hexosaminidase". Proc Natl Acad Sci U S A 82 (4): 1184–8. doi:10.1073/pnas.82.4.1184. PMC 397219. PMID 2579389. 
  2. ^ Korneluk RG, Mahuran DJ, Neote K, Klavins MH, O'Dowd BF, Tropak M, Willard HF, Anderson MJ, Lowden JA, Gravel RA (Jul 1986). "Isolation of cDNA clones coding for the alpha-subunit of human beta-hexosaminidase. Extensive homology between the alpha- and beta-subunits and studies on Tay-Sachs disease". J Biol Chem 261 (18): 8407–13. PMID 3013851. 
  3. ^ a b "Entrez Gene: HEXB hexosaminidase B (beta polypeptide)". 

Further reading[edit]