BGAL_PSEHA
ID BGAL_PSEHA Reviewed; 1039 AA.
AC P81650; Q9ZEM8;
DT 15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 2.
DT 03-AUG-2022, entry version 105.
DE RecName: Full=Beta-galactosidase;
DE Short=Beta-gal;
DE EC=3.2.1.23;
DE AltName: Full=Beta-D-galactoside galactohydrolase;
DE AltName: Full=Lactase;
GN Name=lacZ;
OS Pseudoalteromonas haloplanktis (Alteromonas haloplanktis).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Alteromonadales;
OC Pseudoalteromonadaceae; Pseudoalteromonas.
OX NCBI_TaxID=228;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 2-20, COFACTOR,
RP SUBUNIT, AND BIOPHYSICOCHEMICAL PROPERTIES.
RC STRAIN=TAE 79;
RX PubMed=11282601; DOI=10.1128/aem.67.4.1529-1535.2001;
RA Hoyoux A., Jennes I., Dubois P., Genicot S., Dubail F., Francois J.M.,
RA Baise E., Feller G., Gerday C.;
RT "Cold-adapted beta-galactosidase from the Antarctic psychrophile
RT Pseudoalteromonas haloplanktis.";
RL Appl. Environ. Microbiol. 67:1529-1535(2001).
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;
CC Evidence={ECO:0000305|PubMed:11282601};
CC Note=Binds 2 magnesium ions per monomer. {ECO:0000305|PubMed:11282601};
CC -!- COFACTOR:
CC Name=Na(+); Xref=ChEBI:CHEBI:29101; Evidence={ECO:0000250};
CC Note=Binds 1 sodium ion per monomer. {ECO:0000250};
CC -!- ACTIVITY REGULATION: Inhibited by zinc, copper and nickel ions.
CC Activated by 2-mercaptoethanol and inhibited by EDTA in vitro.
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=2.4 mM for lactose (at pH 7.5 and at 25 degrees Celsius)
CC {ECO:0000269|PubMed:11282601};
CC pH dependence:
CC Optimum pH is 8.5. {ECO:0000269|PubMed:11282601};
CC Temperature dependence:
CC Optimum temperature is 4 degrees Celsius. It does not grow at
CC temperatures higher than 25 degrees Celsius.
CC {ECO:0000269|PubMed:11282601};
CC -!- SUBUNIT: Homotetramer. {ECO:0000305|PubMed:11282601}.
CC -!- BIOTECHNOLOGY: This cold-adapted beta-galactosidase could be used to
CC hydrolyze lactose in milk and dairy products processed in refrigerated
CC plants. It is in fact superior to the current commercial enzyme from
CC K.marxiamus with respect to lactose removal, especially at low
CC temperatures.
CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 2 family. {ECO:0000305}.
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DR EMBL; AJ131635; CAA10470.1; -; Genomic_DNA.
DR AlphaFoldDB; P81650; -.
DR SMR; P81650; -.
DR CAZy; GH2; Glycoside Hydrolase Family 2.
DR eggNOG; COG3250; Bacteria.
DR BRENDA; 3.2.1.23; 5081.
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:0016052; P:carbohydrate catabolic process; IEA:UniProt.
DR Gene3D; 2.60.40.10; -; 2.
DR Gene3D; 2.70.98.10; -; 1.
DR HAMAP; MF_01687; Beta_gal; 1.
DR InterPro; IPR004199; B-gal_small/dom_5.
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; 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; IPR006102; Glyco_hydro_2_Ig-like.
DR InterPro; IPR006104; Glyco_hydro_2_N.
DR InterPro; IPR017853; Glycoside_hydrolase_SF.
DR InterPro; IPR013783; Ig-like_fold.
DR InterPro; IPR032312; LacZ_4.
DR Pfam; PF02929; Bgal_small_N; 1.
DR Pfam; PF16353; DUF4981; 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 PRINTS; PR00132; GLHYDRLASE2.
DR SMART; SM01038; Bgal_small_N; 1.
DR SUPFAM; SSF49303; SSF49303; 2.
DR SUPFAM; SSF49785; SSF49785; 1.
DR SUPFAM; SSF51445; SSF51445; 1.
DR SUPFAM; SSF74650; SSF74650; 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 INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000269|PubMed:11282601"
FT CHAIN 2..1039
FT /note="Beta-galactosidase"
FT /id="PRO_0000057656"
FT ACT_SITE 460
FT /note="Proton donor"
FT /evidence="ECO:0000250"
FT ACT_SITE 536
FT /note="Nucleophile"
FT /evidence="ECO:0000250"
FT BINDING 103
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT BINDING 201
FT /ligand="Na(+)"
FT /ligand_id="ChEBI:CHEBI:29101"
FT /evidence="ECO:0000250"
FT BINDING 201
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT BINDING 415
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 417
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 460
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 460
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT BINDING 536..539
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT BINDING 596
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 600
FT /ligand="Na(+)"
FT /ligand_id="ChEBI:CHEBI:29101"
FT /evidence="ECO:0000250"
FT BINDING 603
FT /ligand="Na(+)"
FT /ligand_id="ChEBI:CHEBI:29101"
FT /evidence="ECO:0000250"
FT BINDING 603
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT BINDING 1012
FT /ligand="substrate"
FT /evidence="ECO:0000250"
FT SITE 356
FT /note="Transition state stabilizer"
FT /evidence="ECO:0000250"
FT SITE 390
FT /note="Transition state stabilizer"
FT /evidence="ECO:0000250"
FT SITE 1012
FT /note="Important for ensuring that an appropriate
FT proportion of lactose is converted to allolactose"
FT /evidence="ECO:0000250"
SQ SEQUENCE 1039 AA; 118199 MW; D77713F653DE8231 CRC64;
MTSLQHIINR RDWENPITVQ VNQVKAHSPL NGFKTIEDAR ENTQSQKKSL NGQWDFKLFD
KPEAVDESLL YEKISKELSG DWQSITVPSN WQLHGFDKPI YCNVKYPFAV NPPFVPSDNP
TGCYRTEFTI TPEQLTQRNH IIFEGVNSAF HLWCNGQWVG YSQDSRLPSE FDLSELLVVG
TNRIAVMVIR WSDGSYLEDQ DMWWLSGIFR DVNLLTKPQS QIRDVFITPD LDACYRDATL
HIKTAINAPN NYQVAVQIFD GKTSLCEPKI QSTNNKRVDE KGGWSDVVFQ TIAIRSPKKW
TAETPYLYRC VVSLLDEQGN TVDVEAYNIG FRKVEMLNGQ LCVNGKPLLI RGVNRHEHHP
ENGHAVSTAD MIEDIKLMKQ NNFNAVRTAH YPNHPLFYEL CDELGLYVVD EANIETHGMF
PMGRLASDPL WAGAFMSRYT QMVERDKNHA SIIIWSLGNE CGHGANHDAM YGWSKSFDPS
RPVQYEGGGA NTTATDIICP MYSRVDTDIK DDAVPKYSIK KWLSLPGETR PLILCEYAHA
MGNSLGSFDD YWQAFREYPR LQGGFIWDWV DQGLSKIDEN GKHYWAYGGD FGDELNDRQF
CINGLLFPDR TPHPSLFEAK YSQQHLQFTL REQNQNQNQN QYSIDVFSDY VFRHTDNEKL
VWQLIQNGVC VEQGEMALNI APQSTHTLTI KTKTAFEHGA QYYLNLDVAL INDSHFANAN
HVMDSEQFKL INSNNLNSKS FASATEKSVI SVNETDSHLS IENNTFKLVF NQQSGLIEQW
LQDDTQVISS PLVDNFYRAP LDNDIGVSEV DNLDPNAWEA RWSRAGIGQW QRTCSSINAV
QSSVDVRITC VFNYEFNGVL QAQTQWLYTL NNTGTISLNV DVNLNDTLPP MPRIGLSTTI
NKQSDTKVNW LGLGPFENYP DRKSAARFGY YSLSLNELYT PYIFPTDNGL RSDCQLLSIN
NLIVTGAFLF AASEYSQNML TQAKHTNELI ADDCIHVHID HQHMGVGGDD SWSPSTHKEY
LLEQKNYNYS LTLTGGITT
