ID HEXB_PIG Reviewed; 531 AA. AC Q29548; DT 30-MAY-2000, integrated into UniProtKB/Swiss-Prot. DT 10-MAY-2005, sequence version 2. DT 24-JAN-2024, entry version 129. DE RecName: Full=Beta-hexosaminidase subunit beta {ECO:0000250|UniProtKB:P07686}; DE EC=3.2.1.52 {ECO:0000250|UniProtKB:P07686}; DE AltName: Full=65 kDa epididymal boar protein; DE AltName: Full=Beta-N-acetylhexosaminidase subunit beta; DE Short=Hexosaminidase subunit B; DE AltName: Full=N-acetyl-beta-glucosaminidase subunit beta; DE Flags: Precursor; GN Name=HEXB {ECO:0000250|UniProtKB:P07686}; OS Sus scrofa (Pig). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; OC Eutheria; Laurasiatheria; Artiodactyla; Suina; Suidae; Sus. OX NCBI_TaxID=9823; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA]. RC TISSUE=Epididymis; RA Syntin P., Okamura N., Guillou F., Dacheux F., Dacheux J.-L.; RT "Purification, cloning and sequencing analysis of B-N-acetyl-hexosaminidase RT from epididymal boar."; RL Submitted (OCT-1995) to the EMBL/GenBank/DDBJ databases. RN [2] RP PARTIAL PROTEIN SEQUENCE. RC TISSUE=Epididymis; RX PubMed=8902205; DOI=10.1095/biolreprod55.5.956; RA Syntin P., Dacheux F., Druart X., Gatti J.L., Okamura N., Dacheux J.-L.; RT "Characterization and identification of proteins secreted in the various RT regions of the adult boar epididymis."; RL Biol. Reprod. 55:956-974(1996). CC -!- FUNCTION: Hydrolyzes the non-reducing end N-acetyl-D-hexosamine and/or CC sulfated N-acetyl-D-hexosamine of glycoconjugates, such as the CC oligosaccharide moieties from proteins and neutral glycolipids, or from CC certain mucopolysaccharides. The isozyme B does not hydrolyze each of CC these substrates, however hydrolyzes efficiently neutral CC oligosaccharide. Only the isozyme A is responsible for the degradation CC of GM2 gangliosides in the presence of GM2A (By similarity). During CC fertilization is responsible, at least in part, for the zona block to CC polyspermy. Present in the cortical granules of non-activated oocytes, CC is exocytosed during the cortical reaction in response to oocyte CC activation and inactivates the sperm galactosyltransferase-binding CC site, accounting for the block in sperm binding to the zona pellucida CC (By similarity). {ECO:0000250|UniProtKB:P07686, CC ECO:0000250|UniProtKB:P20060}. CC -!- CATALYTIC ACTIVITY: CC Reaction=Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine CC residues in N-acetyl-beta-D-hexosaminides.; EC=3.2.1.52; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC -!- CATALYTIC ACTIVITY: CC Reaction=H2O + N-acetyl-beta-D-galactosaminyl-(1->4)-beta-D-3- CC sulfogalactosyl-(1->4)-beta-D-glucosyl-(1<->1')-ceramide = a beta-D- CC 3-sulfogalactosyl-(1->4)-beta-D-glucosyl-(1<->1')-ceramide + N- CC acetyl-beta-D-galactosamine; Xref=Rhea:RHEA:48276, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:28497, ChEBI:CHEBI:90163, ChEBI:CHEBI:90164; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:48277; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC -!- CATALYTIC ACTIVITY: CC Reaction=a ganglioside GM2 (d18:1(4E)) + H2O = a ganglioside GM3 CC (d18:1(4E)) + N-acetyl-beta-D-galactosamine; Xref=Rhea:RHEA:47940, CC ChEBI:CHEBI:15377, ChEBI:CHEBI:28497, ChEBI:CHEBI:60065, CC ChEBI:CHEBI:71502; Evidence={ECO:0000250|UniProtKB:P07686}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:47941; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC -!- CATALYTIC ACTIVITY: CC Reaction=a ganglioside GM2 + H2O = a ganglioside GM3 + N-acetyl-beta-D- CC galactosamine; Xref=Rhea:RHEA:47968, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:28497, ChEBI:CHEBI:79210, ChEBI:CHEBI:79218; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:47969; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC -!- CATALYTIC ACTIVITY: CC Reaction=beta-D-GalNAc-(1->4)-alpha-L-IdoA-(1->3)-beta-D-GalNAc-4- CC sulfate-(1->4)-alpha-L-IdoA-(1->3)-D-GalNAc-4-sulfate + H2O = alpha- CC L-IdoA-(1->3)-beta-D-GalNAc-4-sulfate-(1->4)-alpha-L-IdoA-(1->3)-D- CC GalNAc-4-sulfate + N-acetyl-D-galactosamine; Xref=Rhea:RHEA:64372, CC ChEBI:CHEBI:15377, ChEBI:CHEBI:28037, ChEBI:CHEBI:152565, CC ChEBI:CHEBI:152566; Evidence={ECO:0000250|UniProtKB:P07686}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:64373; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC -!- CATALYTIC ACTIVITY: CC Reaction=H2O + N-acetyl-beta-D-6-sulfogalactosaminyl-(1->4)-alpha-L- CC iduronyl-(1->3)-N-acetyl-D-6-sulfogalactosamine = alpha-L-iduronyl- CC (1->3)-N-acetyl-D-6-sulfogalactosamine + N-acetyl-D-6- CC sulfogalactosamine; Xref=Rhea:RHEA:64384, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:152567, ChEBI:CHEBI:152568, ChEBI:CHEBI:153064; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:64385; CC Evidence={ECO:0000250|UniProtKB:P07686}; CC -!- ACTIVITY REGULATION: Addition of GM2A stimulates the hydrolysis of CC sulfated glycosphingolipid SM2 and the ganglioside GM2. CC {ECO:0000250|UniProtKB:P07686}. CC -!- SUBUNIT: There are 3 forms of beta-hexosaminidase: hexosaminidase A is CC an heterodimer composed of one subunit alpha and one subunit beta CC (chain A and B); hexosaminidase B is an homodimer of two beta subunits CC (two chains A and B); hexosaminidase S is a homodimer of two alpha CC subunits (By similarity). The composition of the dimer (isozyme A CC versus isozyme S) has a significant effect on the substrate specificity CC of the alpha subunit active site (By similarity). CC {ECO:0000250|UniProtKB:P06865, ECO:0000250|UniProtKB:P07686}. CC -!- SUBCELLULAR LOCATION: Lysosome {ECO:0000250|UniProtKB:P07686}. CC Cytoplasmic vesicle, secretory vesicle, Cortical granule CC {ECO:0000250|UniProtKB:P20060}. CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 20 family. {ECO:0000305}. CC -!- SEQUENCE CAUTION: CC Sequence=CAA63123.1; Type=Frameshift; Evidence={ECO:0000305}; CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; X92379; CAA63123.1; ALT_FRAME; mRNA. DR RefSeq; NP_999086.1; NM_213921.1. DR AlphaFoldDB; Q29548; -. DR SMR; Q29548; -. DR STRING; 9823.ENSSSCP00000014965; -. DR CAZy; GH20; Glycoside Hydrolase Family 20. DR GlyCosmos; Q29548; 3 sites, No reported glycans. DR PaxDb; 9823-ENSSSCP00000014965; -. DR PeptideAtlas; Q29548; -. DR GeneID; 396958; -. DR KEGG; ssc:396958; -. DR CTD; 3074; -. DR eggNOG; KOG2499; Eukaryota. DR InParanoid; Q29548; -. DR OrthoDB; 178991at2759; -. DR Proteomes; UP000008227; Unplaced. DR Proteomes; UP000314985; Unplaced. DR Proteomes; UP000694570; Unplaced. DR Proteomes; UP000694571; Unplaced. DR Proteomes; UP000694720; Unplaced. DR Proteomes; UP000694722; Unplaced. DR Proteomes; UP000694723; Unplaced. DR Proteomes; UP000694724; Unplaced. DR Proteomes; UP000694725; Unplaced. DR Proteomes; UP000694726; Unplaced. DR Proteomes; UP000694727; Unplaced. DR Proteomes; UP000694728; Unplaced. DR GO; GO:0060473; C:cortical granule; ISS:UniProtKB. DR GO; GO:0005764; C:lysosome; IBA:GO_Central. DR GO; GO:0016020; C:membrane; IBA:GO_Central. DR GO; GO:0004563; F:beta-N-acetylhexosaminidase activity; ISS:UniProtKB. DR GO; GO:0102148; F:N-acetyl-beta-D-galactosaminidase activity; IEA:UniProtKB-EC. DR GO; GO:0005975; P:carbohydrate metabolic process; IEA:InterPro. DR GO; GO:0006689; P:ganglioside catabolic process; ISS:UniProtKB. DR GO; GO:0030203; P:glycosaminoglycan metabolic process; IBA:GO_Central. DR GO; GO:0007338; P:single fertilization; ISS:UniProtKB. DR CDD; cd06562; GH20_HexA_HexB-like; 1. DR Gene3D; 3.30.379.10; Chitobiase/beta-hexosaminidase domain 2-like; 1. DR Gene3D; 3.20.20.80; Glycosidases; 1. DR InterPro; IPR025705; Beta_hexosaminidase_sua/sub. DR InterPro; IPR015883; Glyco_hydro_20_cat. DR InterPro; IPR017853; Glycoside_hydrolase_SF. DR InterPro; IPR029018; Hex-like_dom2. DR InterPro; IPR029019; HEX_eukaryotic_N. DR PANTHER; PTHR22600; BETA-HEXOSAMINIDASE; 1. DR PANTHER; PTHR22600:SF38; BETA-HEXOSAMINIDASE SUBUNIT BETA; 1. DR Pfam; PF00728; Glyco_hydro_20; 1. DR Pfam; PF14845; Glycohydro_20b2; 1. DR PIRSF; PIRSF001093; B-hxosamndse_ab_euk; 1. DR PRINTS; PR00738; GLHYDRLASE20. DR SUPFAM; SSF51445; (Trans)glycosidases; 1. DR SUPFAM; SSF55545; beta-N-acetylhexosaminidase-like domain; 1. PE 1: Evidence at protein level; KW Cytoplasmic vesicle; Direct protein sequencing; Disulfide bond; KW Glycoprotein; Glycosidase; Hydrolase; Lipid metabolism; Lysosome; KW Reference proteome; Signal. FT SIGNAL 1..21 FT /evidence="ECO:0000255" FT CHAIN 22..531 FT /note="Beta-hexosaminidase subunit beta" FT /id="PRO_0000012007" FT ACT_SITE 329 FT /note="Proton donor" FT /evidence="ECO:0000250" FT CARBOHYD 120 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255" FT CARBOHYD 164 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255" FT CARBOHYD 301 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000255" FT DISULFID 67..111 FT /evidence="ECO:0000250" FT DISULFID 283..334 FT /evidence="ECO:0000250" FT DISULFID 508..525 FT /evidence="ECO:0000250" SQ SEQUENCE 531 AA; 61050 MW; F55D62D6937E51C5 CRC64; MEVLPGLLRL LAALVVAERW ARDTSGAESL GLWPLPFAVD ISPRSLHLSP NNFFFGHSPT SKAGSSCEIL QEAFRRYYDF IFGFYKWHQG SYQLCFGTEL QQLQVHVESE CDTFPSISSN ESYVLHVKGP EALLRANTVW GALRGLETFS QLIYQDSYGT FTVNESEIID FPRFPHRGIL IDTGRHFLSV KTIFKTLDAM AFNKFNVLHW HIVDDQSFPY QSINFGVLSS KGSYSLSHVY TPNDVRMVIE YARIRGIRVM PEFDTPGHSR SWGKGQKDLL TPCYRKQVLS GTFGPINPIL NTTYNFLSKF FKEISTVFPD EFIHIGGDEV DFDCWASNSE ILQFMQEKGF SQISLNSNLC TVFKISNMIS AMKKRPIVWQ EAFDGRDKFM PGTVVQVWKI EDYKWEQSLI TKAGFPVILS APWYLDLISY GQDWKNYYEV EPQDFPGSDK ERKRVLGGEA CLWGEYVDAT NLTPRLWPRA SAVGERLWSH KDVRDIHDAY SRLTIHRCRM VRRGIAAEPL FTGYCNHEHR M //