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Identification
HMDB Protein ID HMDBP00872
Secondary Accession Numbers
  • 6154
Name Beta-hexosaminidase subunit alpha
Synonyms
  1. Beta-N-acetylhexosaminidase subunit alpha
  2. Hexosaminidase subunit A
  3. N-acetyl-beta-glucosaminidase subunit alpha
Gene Name HEXA
Protein Type Enzyme
Biological Properties
General Function Involved in beta-N-acetylhexosaminidase activity
Specific Function Responsible for the degradation of GM2 gangliosides, and a variety of other molecules containing terminal N-acetyl hexosamines, in the brain and other tissues. The form B is active against certain oligosaccharides. The form S has no measurable activity.
Pathways
  • Amino sugar and nucleotide sugar metabolism
  • Amino Sugar Metabolism
  • G(M2)-Gangliosidosis: Variant B, Tay-sachs disease
  • Glycosaminoglycan degradation
  • Glycosphingolipid biosynthesis - ganglio series
  • Glycosphingolipid biosynthesis - globo series
  • Lysosome
  • Other glycan degradation
  • Salla Disease/Infantile Sialic Acid Storage Disease
  • Sialuria or French Type Sialuria
  • Sialuria or French Type Sialuria
  • Tay-Sachs Disease
Reactions
+ Water → + N-Acetyl-b-D-galactosamine details
GO Classification
Biological Process
myelination
sensory perception of sound
neuromuscular process controlling balance
lipid storage
phospholipid metabolic process
keratan sulfate catabolic process
hyaluronan catabolic process
adult walking behavior
neuromuscular process controlling posture
skeletal system development
cell morphogenesis involved in neuron differentiation
ganglioside catabolic process
sexual reproduction
carbohydrate metabolic process
glycosphingolipid metabolic process
cell death
chondroitin sulfate catabolic process
lysosome organization
Cellular Component
lysosomal lumen
membrane
Function
ion binding
cation binding
hexosaminidase activity
beta-n-acetylhexosaminidase activity
binding
catalytic activity
hydrolase activity
hydrolase activity, acting on glycosyl bonds
hydrolase activity, hydrolyzing o-glycosyl compounds
Molecular Function
cation binding
beta-N-acetylhexosaminidase activity
protein heterodimerization activity
Process
metabolic process
primary metabolic process
carbohydrate metabolic process
Cellular Location
  1. Lysosome
Gene Properties
Chromosome Location Not Available
Locus Not Available
SNPs HEXA
Gene Sequence
>1590 bp
ATGACAAGCTCCAGGCTTTGGTTTTCGCTGCTGCTGGCGGCAGCGTTCGCAGGACGGGCG
ACGGCCCTCTGGCCCTGGCCTCAGAACTTCCAAACCTCCGACCAGCGCTACGTCCTTTAC
CCGAACAACTTTCAATTCCAGTACGATGTCAGCTCGGCCGCGCAGCCCGGCTGCTCAGTC
CTCGACGAGGCCTTCCAGCGCTATCGTGACCTGCTTTTCGGTTCCGGGTCTTGGCCCCGT
CCTTACCTCACAGGGAAACGGCATACACTGGAGAAGAATGTGTTGGTTGTCTCTGTAGTC
ACACCTGGATGTAACCAGCTTCCTACTTTGGAGTCAGTGGAGAATTATACCCTGACCATA
AATGATGACCAGTGTTTACTCCTCTCTGAGACTGTCTGGGGAGCTCTCCGAGGTCTGGAG
ACTTTTAGCCAGCTTGTTTGGAAATCTGCTGAGGGCACATTCTTTATCAACAAGACTGAG
ATTGAGGACTTTCCCCGCTTTCCTCACCGGGGCTTGCTGTTGGATACATCTCGCCATTAC
CTGCCACTCTCTAGCATCCTGGACACTCTGGATGTCATGGCGTACAATAAATTGAACGTG
TTCCACTGGCATCTGGTAGATGATCCTTCCTTCCCATATGAGAGCTTCACTTTTCCAGAG
CTCATGAGAAAGGGGTCCTACAACCCTGTCACCCACATCTACACAGCACAGGATGTGAAG
GAGGTCATTGAATACGCACGGCTCCGGGGTATCCGTGTGCTTGCAGAGTTTGACACTCCT
GGCCACACTTTGTCCTGGGGACCAGGTATCCCTGGATTACTGACTCCTTGCTACTCTGGG
TCTGAGCCCTCTGGCACCTTTGGACCAGTGAATCCCAGTCTCAATAATACCTATGAGTTC
ATGAGCACATTCTTCTTAGAAGTCAGCTCTGTCTTCCCAGATTTTTATCTTCATCTTGGA
GGAGATGAGGTTGATTTCACCTGCTGGAAGCCCAACCCAGAGATCCAGGACTTTATGAGG
AAGAAAGGCTTCGGTGAGGACTTCAAGCAGCTGGAGTCCTTCTACATCCAGACGCTGCTG
GACATCGTCTCTTCTTATGGCAAGGGCTATGTGGTGTGGCAGGAGGTGTTTGATAATAAA
GTAAAGATTCAGCCAGACACAATCATACAGGTGTGGCGAGAGGATATTCCAGTGAACTAT
ATGAAGGAGCTGGAACTGGTCACCAAGGCCGGCTTCCGGGCCCTTCTCTCTGCCCCCTGG
TACCTGAACCGTATATCCTACGGCCCTGACTGGAAGGATTTCTACGTAGTGGAACCCCTG
GCATTTGAAGGTACCCCTGAGCAGAAGGCTCTGGTGATTGGTGGAGAGGCTTGTATGTGG
GGAGAATATGTGGACAACACAAACCTGGTCCCCAGGCTCTGGCCCAGAGCAGGGGCTGTT
GCCGAAAGGCTGTGGAGCAACAAGTTGACATCTGACCTGACATTTGCCTATGAACGTTTG
TCACACTTCCGCTGTGAGTTGCTGAGGCGAGGTGTCCAGGCCCAACCCCTCAATGTAGGC
TTCTGTGAGCAGGAGTTTGAACAGACCTGA
Protein Properties
Number of Residues 529
Molecular Weight Not Available
Theoretical pI Not Available
Pfam Domain Function
Signals Not Available
Transmembrane Regions Not Available
Protein Sequence
>Beta-hexosaminidase subunit alpha
MTSSRLWFSLLLAAAFAGRATALWPWPQNFQTSDQRYVLYPNNFQFQYDVSSAAQPGCSV
LDEAFQRYRDLLFGSGSWPRPYLTGKRHTLEKNVLVVSVVTPGCNQLPTLESVENYTLTI
NDDQCLLLSETVWGALRGLETFSQLVWKSAEGTFFINKTEIEDFPRFPHRGLLLDTSRHY
LPLSSILDTLDVMAYNKLNVFHWHLVDDPSFPYESFTFPELMRKGSYNPVTHIYTAQDVK
EVIEYARLRGIRVLAEFDTPGHTLSWGPGIPGLLTPCYSGSEPSGTFGPVNPSLNNTYEF
MSTFFLEVSSVFPDFYLHLGGDEVDFTCWKSNPEIQDFMRKKGFGEDFKQLESFYIQTLL
DIVSSYGKGYVVWQEVFDNKVKIQPDTIIQVWREDIPVNYMKELELVTKAGFRALLSAPW
YLNRISYGPDWKDFYVVEPLAFEGTPEQKALVIGGEACMWGEYVDNTNLVPRLWPRAGAV
AERLWSNKLTSDLTFAYERLSHFRCELLRRGVQAQPLNVGFCEQEFEQT
GenBank ID Protein 62896563
UniProtKB/Swiss-Prot ID P06865
UniProtKB/Swiss-Prot Entry Name HEXA_HUMAN
PDB IDs
GenBank Gene ID AK222502
GeneCard ID HEXA
GenAtlas ID HEXA
HGNC ID HGNC:4878
References
General References
  1. Chen R, Jiang X, Sun D, Han G, Wang F, Ye M, Wang L, Zou H: Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry. J Proteome Res. 2009 Feb;8(2):651-61. doi: 10.1021/pr8008012. [PubMed:19159218 ]
  2. Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. 2004 Oct;14(10B):2121-7. [PubMed:15489334 ]
  3. Bechtel S, Rosenfelder H, Duda A, Schmidt CP, Ernst U, Wellenreuther R, Mehrle A, Schuster C, Bahr A, Blocker H, Heubner D, Hoerlein A, Michel G, Wedler H, Kohrer K, Ottenwalder B, Poustka A, Wiemann S, Schupp I: The full-ORF clone resource of the German cDNA Consortium. BMC Genomics. 2007 Oct 31;8:399. [PubMed:17974005 ]
  4. Korneluk RG, Mahuran DJ, Neote K, Klavins MH, O'Dowd BF, Tropak M, Willard HF, Anderson MJ, Lowden JA, Gravel RA: 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. 1986 Jun 25;261(18):8407-13. [PubMed:3013851 ]
  5. Mahuran DJ, Neote K, Klavins MH, Leung A, Gravel RA: Proteolytic processing of pro-alpha and pro-beta precursors from human beta-hexosaminidase. Generation of the mature alpha and beta a beta b subunits. J Biol Chem. 1988 Apr 5;263(10):4612-8. [PubMed:2965147 ]
  6. O'Dowd BF, Cumming DA, Gravel RA, Mahuran D: Oligosaccharide structure and amino acid sequence of the major glycopeptides of mature human beta-hexosaminidase. Biochemistry. 1988 Jul 12;27(14):5216-26. [PubMed:2971395 ]
  7. Tews I, Perrakis A, Oppenheim A, Dauter Z, Wilson KS, Vorgias CE: Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay-Sachs disease. Nat Struct Biol. 1996 Jul;3(7):638-48. [PubMed:8673609 ]
  8. Mahuran DJ: The biochemistry of HEXA and HEXB gene mutations causing GM2 gangliosidosis. Biochim Biophys Acta. 1991 Feb 22;1096(2):87-94. [PubMed:1825792 ]
  9. Myerowitz R, Piekarz R, Neufeld EF, Shows TB, Suzuki K: Human beta-hexosaminidase alpha chain: coding sequence and homology with the beta chain. Proc Natl Acad Sci U S A. 1985 Dec;82(23):7830-4. [PubMed:2933746 ]
  10. Proia RL, Soravia E: Organization of the gene encoding the human beta-hexosaminidase alpha-chain. J Biol Chem. 1987 Apr 25;262(12):5677-81. [PubMed:2952641 ]
  11. Triggs-Raine BL, Akerman BR, Clarke JT, Gravel RA: Sequence of DNA flanking the exons of the HEXA gene, and identification of mutations in Tay-Sachs disease. Am J Hum Genet. 1991 Nov;49(5):1041-54. [PubMed:1833974 ]
  12. Weitz G, Proia RL: Analysis of the glycosylation and phosphorylation of the alpha-subunit of the lysosomal enzyme, beta-hexosaminidase A, by site-directed mutagenesis. J Biol Chem. 1992 May 15;267(14):10039-44. [PubMed:1533633 ]
  13. Tse R, Vavougios G, Hou Y, Mahuran DJ: Identification of an active acidic residue in the catalytic site of beta-hexosaminidase. Biochemistry. 1996 Jun 11;35(23):7599-607. [PubMed:8652542 ]
  14. Myerowitz R: Tay-Sachs disease-causing mutations and neutral polymorphisms in the Hex A gene. Hum Mutat. 1997;9(3):195-208. [PubMed:9090523 ]
  15. Nakano T, Muscillo M, Ohno K, Hoffman AJ, Suzuki K: A point mutation in the coding sequence of the beta-hexosaminidase alpha gene results in defective processing of the enzyme protein in an unusual GM2-gangliosidosis variant. J Neurochem. 1988 Sep;51(3):984-7. [PubMed:2970528 ]
  16. Navon R, Proia RL: The mutations in Ashkenazi Jews with adult GM2 gangliosidosis, the adult form of Tay-Sachs disease. Science. 1989 Mar 17;243(4897):1471-4. [PubMed:2522679 ]
  17. Tanaka A, Punnett HH, Suzuki K: A new point mutation in the beta-hexosaminidase alpha subunit gene responsible for infantile Tay-Sachs disease in a non-Jewish Caucasian patient (a Kpn mutant). Am J Hum Genet. 1990 Sep;47(3):568-74. [PubMed:2144098 ]
  18. Akli S, Chelly J, Lacorte JM, Poenaru L, Kahn A: Seven novel Tay-Sachs mutations detected by chemical mismatch cleavage of PCR-amplified cDNA fragments. Genomics. 1991 Sep;11(1):124-34. [PubMed:1837283 ]
  19. Mules EH, Hayflick S, Miller CS, Reynolds LW, Thomas GH: Six novel deleterious and three neutral mutations in the gene encoding the alpha-subunit of hexosaminidase A in non-Jewish individuals. Am J Hum Genet. 1992 Apr;50(4):834-41. [PubMed:1532289 ]
  20. Triggs-Raine BL, Mules EH, Kaback MM, Lim-Steele JS, Dowling CE, Akerman BR, Natowicz MR, Grebner EE, Navon R, Welch JP, et al.: A pseudodeficiency allele common in non-Jewish Tay-Sachs carriers: implications for carrier screening. Am J Hum Genet. 1992 Oct;51(4):793-801. [PubMed:1384323 ]
  21. Fernandes M, Kaplan F, Natowicz M, Prence E, Kolodny E, Kaback M, Hechtman P: A new Tay-Sachs disease B1 allele in exon 7 in two compound heterozygotes each with a second novel mutation. Hum Mol Genet. 1992 Dec;1(9):759-61. [PubMed:1302612 ]
  22. Trop I, Kaplan F, Brown C, Mahuran D, Hechtman P: A glycine250--> aspartate substitution in the alpha-subunit of hexosaminidase A causes juvenile-onset Tay-Sachs disease in a Lebanese-Canadian family. Hum Mutat. 1992;1(1):35-9. [PubMed:1301189 ]
  23. Akalin N, Shi HP, Vavougios G, Hechtman P, Lo W, Scriver CR, Mahuran D, Kaplan F: Novel Tay-Sachs disease mutations from China. Hum Mutat. 1992;1(1):40-6. [PubMed:1301190 ]
  24. Cao Z, Natowicz MR, Kaback MM, Lim-Steele JS, Prence EM, Brown D, Chabot T, Triggs-Raine BL: A second mutation associated with apparent beta-hexosaminidase A pseudodeficiency: identification and frequency estimation. Am J Hum Genet. 1993 Dec;53(6):1198-205. [PubMed:7902672 ]
  25. Akli S, Chomel JC, Lacorte JM, Bachner L, Kahn A, Poenaru L: Ten novel mutations in the HEXA gene in non-Jewish Tay-Sachs patients. Hum Mol Genet. 1993 Jan;2(1):61-7. [PubMed:8490625 ]
  26. Harmon DL, Gardner-Medwin D, Stirling JL: Two new mutations in a late infantile Tay-Sachs patient are both in exon 1 of the beta-hexosaminidase alpha subunit gene. J Med Genet. 1993 Feb;30(2):123-8. [PubMed:8445615 ]
  27. Tomczak J, Grebner EE: Three novel beta-hexosaminidase A mutations in obligate carriers of Tay-Sachs disease. Hum Mutat. 1994;4(1):71-2. [PubMed:7951261 ]
  28. Tanaka A, Sakazaki H, Murakami H, Isshiki G, Suzuki K: Molecular genetics of Tay-Sachs disease in Japan. J Inherit Metab Dis. 1994;17(5):593-600. [PubMed:7837766 ]
  29. Triggs-Raine B, Richard M, Wasel N, Prence EM, Natowicz MR: Mutational analyses of Tay-Sachs disease: studies on Tay-Sachs carriers of French Canadian background living in New England. Am J Hum Genet. 1995 Apr;56(4):870-9. [PubMed:7717398 ]
  30. Peleg L, Meltzer F, Karpati M, Goldman B: GM2 gangliosidosis B1 variant: biochemical and molecular characterization of hexosaminidase A. Biochem Mol Med. 1995 Apr;54(2):126-32. [PubMed:8581357 ]
  31. Navon R, Khosravi R, Korczyn T, Masson M, Sonnino S, Fardeau M, Eymard B, Lefevre M, Turpin JC, Rondot P, et al.: A new mutation in the HEXA gene associated with a spinal muscular atrophy phenotype. Neurology. 1995 Mar;45(3 Pt 1):539-43. [PubMed:7898712 ]
  32. De Gasperi R, Gama Sosa MA, Battistini S, Yeretsian J, Raghavan S, Zelnik N, Leshinsky E, Kolodny EH: Late-onset GM2 gangliosidosis: Ashkenazi Jewish family with an exon 5 mutation (Tyr180-->His) in the Hex A alpha-chain gene. Neurology. 1996 Aug;47(2):547-52. [PubMed:8757036 ]
  33. Akerman BR, Natowicz MR, Kaback MM, Loyer M, Campeau E, Gravel RA: Novel mutations and DNA-based screening in non-Jewish carriers of Tay-Sachs disease. Am J Hum Genet. 1997 May;60(5):1099-106. [PubMed:9150157 ]
  34. Kaufman M, Grinshpun-Cohen J, Karpati M, Peleg L, Goldman B, Akstein E, Adam A, Navon R: Tay-Sachs disease and HEXA mutations among Moroccan Jews. Hum Mutat. 1997;10(4):295-300. [PubMed:9338583 ]
  35. Gil Ribeiro M, Pinto RA, Suzuki K, Sa Miranda MC: Two novel (1334delC and 1363G to A, G455R) mutations in exon 12 of the beta-hexosaminidase alpha-chain gene in two Portuguese patients. Hum Mutat. 1997;10(5):359-60. [PubMed:9375850 ]
  36. Drucker L, Hemli JA, Navon R: Two mutated HEXA alleles in a Druze patient with late-infantile Tay-Sachs disease. Hum Mutat. 1997;10(6):451-7. [PubMed:9401008 ]
  37. Petroulakis E, Cao Z, Clarke JT, Mahuran DJ, Lee G, Triggs-Raine B: W474C amino acid substitution affects early processing of the alpha-subunit of beta-hexosaminidase A and is associated with subacute G(M2) gangliosidosis. Hum Mutat. 1998;11(6):432-42. [PubMed:9603435 ]
  38. Tanaka A, Hoang LT, Nishi Y, Maniwa S, Oka M, Yamano T: Different attenuated phenotypes of GM2 gangliosidosis variant B in Japanese patients with HEXA mutations at codon 499, and five novel mutations responsible for infantile acute form. J Hum Genet. 2003;48(11):571-4. Epub 2003 Oct 18. [PubMed:14566483 ]