HEXB_RAT
ID HEXB_RAT Reviewed; 537 AA.
AC Q6AXR4;
DT 10-MAY-2005, integrated into UniProtKB/Swiss-Prot.
DT 13-SEP-2004, sequence version 1.
DT 03-AUG-2022, entry version 114.
DE RecName: Full=Beta-hexosaminidase subunit beta {ECO:0000305};
DE EC=3.2.1.52 {ECO:0000250|UniProtKB:P07686};
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:0000312|RGD:1307607};
OS Rattus norvegicus (Rat).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae;
OC Murinae; Rattus.
OX NCBI_TaxID=10116;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Kidney;
RX PubMed=15489334; DOI=10.1101/gr.2596504;
RG The MGC Project Team;
RT "The status, quality, and expansion of the NIH full-length cDNA project:
RT the Mammalian Gene Collection (MGC).";
RL Genome Res. 14:2121-2127(2004).
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=ganglioside GM2 (d18:1(4E)) + H2O = 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=ganglioside GM2 + H2O = 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}.
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DR EMBL; BC079376; AAH79376.1; -; mRNA.
DR RefSeq; NP_001011946.1; NM_001011946.1.
DR AlphaFoldDB; Q6AXR4; -.
DR SMR; Q6AXR4; -.
DR STRING; 10116.ENSRNOP00000044480; -.
DR CAZy; GH20; Glycoside Hydrolase Family 20.
DR GlyGen; Q6AXR4; 3 sites.
DR iPTMnet; Q6AXR4; -.
DR PhosphoSitePlus; Q6AXR4; -.
DR jPOST; Q6AXR4; -.
DR PeptideAtlas; Q6AXR4; -.
DR PRIDE; Q6AXR4; -.
DR Ensembl; ENSRNOT00000097138; ENSRNOP00000081104; ENSRNOG00000025274.
DR GeneID; 294673; -.
DR KEGG; rno:294673; -.
DR UCSC; RGD:1307607; rat.
DR CTD; 3074; -.
DR RGD; 1307607; Hexb.
DR eggNOG; KOG2499; Eukaryota.
DR GeneTree; ENSGT00390000008107; -.
DR InParanoid; Q6AXR4; -.
DR OrthoDB; 545162at2759; -.
DR PhylomeDB; Q6AXR4; -.
DR Reactome; R-RNO-1660662; Glycosphingolipid metabolism.
DR Reactome; R-RNO-2022857; Keratan sulfate degradation.
DR Reactome; R-RNO-2024101; CS/DS degradation.
DR Reactome; R-RNO-2160916; Hyaluronan uptake and degradation.
DR Reactome; R-RNO-6798695; Neutrophil degranulation.
DR SABIO-RK; Q6AXR4; -.
DR PRO; PR:Q6AXR4; -.
DR Proteomes; UP000002494; Chromosome 2.
DR GO; GO:0001669; C:acrosomal vesicle; ISO:RGD.
DR GO; GO:0042582; C:azurophil granule; ISO:RGD.
DR GO; GO:1905379; C:beta-N-acetylhexosaminidase complex; ISO:RGD.
DR GO; GO:0060473; C:cortical granule; ISS:UniProtKB.
DR GO; GO:0005615; C:extracellular space; ISO:RGD.
DR GO; GO:0005764; C:lysosome; IDA:RGD.
DR GO; GO:0016020; C:membrane; ISO:RGD.
DR GO; GO:0008375; F:acetylglucosaminyltransferase activity; ISO:RGD.
DR GO; GO:0016231; F:beta-N-acetylglucosaminidase activity; IDA:RGD.
DR GO; GO:0004563; F:beta-N-acetylhexosaminidase activity; ISO:RGD.
DR GO; GO:0030246; F:carbohydrate binding; IDA:RGD.
DR GO; GO:0015929; F:hexosaminidase activity; IDA:RGD.
DR GO; GO:0016787; F:hydrolase activity; ISO:RGD.
DR GO; GO:0042802; F:identical protein binding; IPI:RGD.
DR GO; GO:0102148; F:N-acetyl-beta-D-galactosaminidase activity; IEA:UniProtKB-EC.
DR GO; GO:0044877; F:protein-containing complex binding; IDA:RGD.
DR GO; GO:0043615; P:astrocyte cell migration; ISO:RGD.
DR GO; GO:0006874; P:cellular calcium ion homeostasis; ISO:RGD.
DR GO; GO:0006689; P:ganglioside catabolic process; ISS:UniProtKB.
DR GO; GO:0030203; P:glycosaminoglycan metabolic process; ISO:RGD.
DR GO; GO:0006687; P:glycosphingolipid metabolic process; ISO:RGD.
DR GO; GO:0019915; P:lipid storage; ISO:RGD.
DR GO; GO:0007626; P:locomotory behavior; ISO:RGD.
DR GO; GO:0007040; P:lysosome organization; ISO:RGD.
DR GO; GO:0008049; P:male courtship behavior; ISO:RGD.
DR GO; GO:0042552; P:myelination; ISO:RGD.
DR GO; GO:0006044; P:N-acetylglucosamine metabolic process; IDA:RGD.
DR GO; GO:0050905; P:neuromuscular process; ISO:RGD.
DR GO; GO:0050885; P:neuromuscular process controlling balance; ISO:RGD.
DR GO; GO:0009313; P:oligosaccharide catabolic process; ISO:RGD.
DR GO; GO:0048477; P:oogenesis; ISO:RGD.
DR GO; GO:0007341; P:penetration of zona pellucida; ISO:RGD.
DR GO; GO:0008654; P:phospholipid biosynthetic process; ISO:RGD.
DR GO; GO:0045944; P:positive regulation of transcription by RNA polymerase II; ISO:RGD.
DR GO; GO:0008360; P:regulation of cell shape; ISO:RGD.
DR GO; GO:0007605; P:sensory perception of sound; ISO:RGD.
DR GO; GO:0019953; P:sexual reproduction; ISO:RGD.
DR GO; GO:0007338; P:single fertilization; ISS:UniProtKB.
DR GO; GO:0001501; P:skeletal system development; ISO:RGD.
DR Gene3D; 3.30.379.10; -; 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; PTHR22600; 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; SSF51445; 1.
DR SUPFAM; SSF55545; SSF55545; 1.
PE 2: Evidence at transcript level;
KW Cytoplasmic vesicle; Disulfide bond; Glycoprotein; Glycosidase; Hydrolase;
KW Lipid metabolism; Lysosome; Reference proteome; Signal.
FT SIGNAL 1..23
FT /evidence="ECO:0000255"
FT CHAIN 24..537
FT /note="Beta-hexosaminidase subunit beta"
FT /id="PRO_0000012008"
FT ACT_SITE 333
FT /note="Proton donor"
FT /evidence="ECO:0000250"
FT CARBOHYD 62
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 168
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT CARBOHYD 305
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255"
FT DISULFID 69..115
FT /evidence="ECO:0000250"
FT DISULFID 287..338
FT /evidence="ECO:0000250"
FT DISULFID 512..529
FT /evidence="ECO:0000250"
SQ SEQUENCE 537 AA; 61527 MW; 1A9BB01F4AD2F6E4 CRC64;
MPGSPRRAPG LLLQALVAMV SLALVAPFGL QPALWPMPRS VQVFPRLLYI SPENFQIDNS
PNSTAGPSCS LLLEAFRRYY NYIFGFYKRH HGPAKFQDKP QLEKLLVFIN LEPQCDAFPS
MSSDESYSLL VQEPVALLKA NEVWGALRGL ETFSQLVYQD AYGTFTINES TIADSPRFPH
RGILIDTSRH YLPVKTIFKT LDAMAFNKFN VLHWHIVDDQ SFPYQSITFP ELSNKGSYSL
SHVYTPNDIH MVLEYARLRG IRVIPEFDSP GHTQSWGKGQ KNLLTPCFIQ KIRTQKVGPV
DPSLNTTYVF FDTFFKEISR VFPDQFIHLG GDEVEFECWA SNPNIQNFMK KKGFGNNFRR
LESFYIKKIL DIITSLKKSS IVWQDVFDDQ VELQPGTVVE VWKSENYLNE LAQVTASGFP
AILSAPWYLD LISYGQDWRN YYKAEPLNFE GSEKQKQLVI GGEACLWGEY VDATNLIPRL
WPRASAVGER LWSPRIITNL ENAYRRLAVH RCRMVSRGIA AQPLFTGYCN YENKMEK
