ID   BGAL_ENTAG              Reviewed;        1028 AA.
AC   A3FEW8;
DT   24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT   24-MAR-2009, sequence version 2.
DT   02-SEP-2026, entry version 64.
DE   RecName: Full=Beta-galactosidase;
DE            Short=Beta-gal;
DE            Short=Bga;
DE            EC=3.2.1.23;
DE   AltName: Full=Lactase;
DE   AltName: Full=Transglycosylating beta-galactosidase;
GN   Name=lacZ;
OS   Enterobacter agglomerans (Erwinia herbicola) (Pantoea agglomerans).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Erwiniaceae; Pantoea; Pantoea agglomerans group.
OX   NCBI_TaxID=549;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-9, FUNCTION AS
RP   TRANSGLYCOSYLATING BETA-GALACTOSIDASE, BIOPHYSICOCHEMICAL PROPERTIES,
RP   ACTIVITY REGULATION, AND SUBUNIT.
RC   STRAIN=B1;
RX   PubMed=17336932; DOI=10.1016/j.bbrc.2007.02.106;
RA   Lu L., Xiao M., Xu X., Li Z., Li Y.;
RT   "A novel beta-galactosidase capable of glycosyl transfer from Enterobacter
RT   agglomerans B1.";
RL   Biochem. Biophys. Res. Commun. 356:78-84(2007).
CC   -!- FUNCTION: This beta-galactosidase is also able to catalyze glycosyl
CC       transfer to a series of acceptors, including hexose, pentose, beta- or
CC       alpha-disaccharides, hexahydroxy alcohol, cyclitol, and aromatic
CC       glycosides, resulting in the production of galacto-oligosaccharides
CC       (GOS). {ECO:0000269|PubMed:17336932}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of terminal non-reducing beta-D-galactose residues
CC         in beta-D-galactosides.; EC=3.2.1.23;
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000305};
CC       Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000305};
CC       Name=Fe cation; Xref=ChEBI:CHEBI:24875; Evidence={ECO:0000305};
CC       Note=Binds 2 magnesium ions per monomer. Can also use manganese and
CC       iron. {ECO:0000305};
CC   -!- COFACTOR:
CC       Name=Na(+); Xref=ChEBI:CHEBI:29101; Evidence={ECO:0000305};
CC       Name=K(+); Xref=ChEBI:CHEBI:29103; Evidence={ECO:0000305};
CC       Note=Binds 1 sodium ion per monomer. Can also use potassium.
CC       {ECO:0000305};
CC   -!- ACTIVITY REGULATION: Completely inhibited by Hg(2+), Cu(2+) Ag(2+), and
CC       partially inhibited by Zn(2+), imidazole and EDTA. Activated by Ca(2+),
CC       Co(2+), Ni(2+). {ECO:0000269|PubMed:17336932}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=0.06 mM for o-nitrophenyl-beta-D-galactopyranoside (at 37 degrees
CC         Celsius) {ECO:0000269|PubMed:17336932};
CC         KM=114 mM for lactose (at 37 degrees Celsius)
CC         {ECO:0000269|PubMed:17336932};
CC         Vmax=0.43 mmol/min/mg enzyme for
CC         o-nitrophenyl-beta-D-galactopyranoside (at 37 degrees Celsius)
CC         {ECO:0000269|PubMed:17336932};
CC         Vmax=2.9 mmol/min/mg enzyme for
CC         o-nitrophenyl-beta-D-galactopyranoside (at 37 degrees Celsius)
CC         {ECO:0000269|PubMed:17336932};
CC       pH dependence:
CC         Optimum pH is 7.5-8.0. Stable between 7.5-10.0.
CC         {ECO:0000269|PubMed:17336932};
CC       Temperature dependence:
CC         Optimum temperature is 37-40 degrees Celsius. Stable below 37 degrees
CC         Celsius. {ECO:0000269|PubMed:17336932};
CC   -!- SUBUNIT: Homodimer. {ECO:0000269|PubMed:17336932}.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 2 family. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=ABN42680.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; EF371803; ABN42680.1; ALT_INIT; Genomic_DNA.
DR   AlphaFoldDB; A3FEW8; -.
DR   SMR; A3FEW8; -.
DR   CAZy; GH2; Glycoside Hydrolase Family 2.
DR   SABIO-RK; A3FEW8; -.
DR   GO; GO:0009341; C:beta-galactosidase complex; IEA:InterPro.
DR   GO; GO:0004565; F:beta-galactosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0030246; F:carbohydrate binding; IEA:InterPro.
DR   GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0005990; P:lactose catabolic process; IEA:TreeGrafter.
DR   FunFam; 2.60.40.10:FF:000680; Beta-galactosidase; 1.
DR   FunFam; 3.20.20.80:FF:000018; Beta-galactosidase; 1.
DR   Gene3D; 2.70.98.10; -; 1.
DR   Gene3D; 2.60.120.260; Galactose-binding domain-like; 1.
DR   Gene3D; 3.20.20.80; Glycosidases; 1.
DR   Gene3D; 2.60.40.10; Immunoglobulins; 2.
DR   HAMAP; MF_01687; Beta_gal; 1.
DR   InterPro; IPR004199; B-gal_small/dom_5.
DR   InterPro; IPR050347; Bact_Beta-galactosidase.
DR   InterPro; IPR036156; Beta-gal/glucu_dom_sf.
DR   InterPro; IPR011013; Gal_mutarotase_sf_dom.
DR   InterPro; IPR008979; Galactose-bd-like_sf.
DR   InterPro; IPR014718; GH-type_carb-bd.
DR   InterPro; IPR017853; GH_hydrolase_sf.
DR   InterPro; IPR006101; Glyco_hydro_2.
DR   InterPro; IPR023232; Glyco_hydro_2_AS.
DR   InterPro; IPR023933; Glyco_hydro_2_beta_Galsidase.
DR   InterPro; IPR006103; Glyco_hydro_2_cat.
DR   InterPro; IPR023230; Glyco_hydro_2_CS.
DR   InterPro; IPR006104; Glyco_hydro_2_N.
DR   InterPro; IPR013783; Ig-like_fold.
DR   InterPro; IPR006102; Ig-like_GH2.
DR   InterPro; IPR032312; LacZ_4.
DR   NCBIfam; NF007074; PRK09525.1; 1.
DR   PANTHER; PTHR46323; BETA-GALACTOSIDASE; 1.
DR   PANTHER; PTHR46323:SF2; BETA-GALACTOSIDASE; 1.
DR   Pfam; PF02929; Bgal_small_N; 1.
DR   Pfam; PF00703; Glyco_hydro_2; 1.
DR   Pfam; PF02836; Glyco_hydro_2_C; 1.
DR   Pfam; PF02837; Glyco_hydro_2_N; 1.
DR   Pfam; PF16353; LacZ_4; 1.
DR   PRINTS; PR00132; GLHYDRLASE2.
DR   SMART; SM01038; Bgal_small_N; 1.
DR   SUPFAM; SSF51445; (Trans)glycosidases; 1.
DR   SUPFAM; SSF49303; beta-Galactosidase/glucuronidase domain; 2.
DR   SUPFAM; SSF74650; Galactose mutarotase-like; 1.
DR   SUPFAM; SSF49785; Galactose-binding domain-like; 1.
DR   PROSITE; PS00719; GLYCOSYL_HYDROL_F2_1; 1.
DR   PROSITE; PS00608; GLYCOSYL_HYDROL_F2_2; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Glycosidase; Hydrolase; Magnesium;
KW   Metal-binding; Sodium.
FT   CHAIN           1..1028
FT                   /note="Beta-galactosidase"
FT                   /id="PRO_0000366982"
FT   ACT_SITE        463
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        539
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   BINDING         104
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         203
FT                   /ligand="Na(+)"
FT                   /ligand_id="ChEBI:CHEBI:29101"
FT                   /evidence="ECO:0000250"
FT   BINDING         203
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         418
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250"
FT   BINDING         420
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250"
FT   BINDING         463
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250"
FT   BINDING         463
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         539..542
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         599
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250"
FT   BINDING         603
FT                   /ligand="Na(+)"
FT                   /ligand_id="ChEBI:CHEBI:29101"
FT                   /evidence="ECO:0000250"
FT   BINDING         606
FT                   /ligand="Na(+)"
FT                   /ligand_id="ChEBI:CHEBI:29101"
FT                   /evidence="ECO:0000250"
FT   BINDING         606
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         1004
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   SITE            359
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250"
FT   SITE            393
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250"
FT   SITE            1004
FT                   /note="Important for ensuring that an appropriate
FT                   proportion of lactose is converted to allolactose"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   1028 AA;  116394 MW;  5A72487AB243185D CRC64;
     MFTASPMSLS KILARRDWEN PGVTQWHRLP AHAPFNSWRD EASARADDNA SRKRSLNGDW
     QFSYYAAPEQ VPDSWVTEDC ADAVTTPVPS NWQMQGFDTP IYTNDTYPIP VNPPFVPAEN
     PTGCYSLTFE VDEQWLESGQ TRIVFDGVNS AFYLWCNGKW MGYSQDSRLP AEFDLSAVLR
     PGTNRLAVLV LRWCDGSYLE DQDMWRMSGI FRDVSLLHKP HTHIADYHAV TELNADYDRA
     KLQVEVALAG EQFADCEVAV TLWRDGLSVA TVSAKPGSAI IDERGNWAER LNVTLPVKDP
     ALWSAETPEL YRLTFALRDG QGEILDVEAC DVGFRCVEIS NGLLKVNGKP LLIRGVNRHE
     HHPENGQVMD EATMCRDIEL MKQHNFNAVR CSHYPNHPLW YTLCDRYGLY VVDEANIETH
     GMVPMSRLAD DPRWLPAMSE RVTRMVLRDR NHPSIIIWSL GNESGHGANH DALYRWVKTT
     DPTRPVQYEG GGANTAATDI VCPMYARVDQ DQPFEAVPKW SLKKWIGMPD ETRPLILCEY
     AHAMGNSFGG FAKYWQAFRN HPRLQGGFVW DWVDQALTKK DDNGNAFWAY GGDFGDTPND
     RQFCLNGLVF PDRTPHPALF EAQRAQQFFT FTLVSTSPLV IDVHSDYLFR QCDNEQLRWN
     IARDGEVLAS GEVALTIAPQ QTQRIEIDAP EFAAAAGEIW LNVDIVQTAA TAWSPADHRC
     AWDQWQLPAP LYIAPPVEGT AKPDLKVKED VLEVSHQSQR WHFDRASGNL TQWWNNGTAT
     LLAPLSDNFT RAPLDNDIGV SEATRIDPNA WVERWKAAGM YNLTPRLLLC EGEQLAQAVT
     ITTLHAWESN GKALFLSRKV WKIDRAGVLH GDVQVQVAND IPQPARIGLS CQLAQTPQTA
     SWLGLGPDEN YPDRKLAARQ GRWTLPLDAL HTAYIFPTDN GLRCDTRELT FDTHQMQGDF
     HFSLSRYSQQ QLRDTSHHHL LEAEPGCWLN IDAFHMGVGG DDSWSPSVSP EFILQRREMR
     YAFSWRQD
//