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 27-MAR-2024, entry version 110. 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; Pseudomonadota; 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}. 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; 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:0005975; P:carbohydrate metabolic process; IEA:InterPro. DR GO; GO:1901575; P:organic substance catabolic process; IEA:UniProt. 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; 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 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 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 //