ID   BGAL1_LACAC             Reviewed;         667 AA.
AC   Q5FJ41; B2LWG4;
DT   03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2005, sequence version 1.
DT   27-MAR-2024, entry version 86.
DE   RecName: Full=Beta-galactosidase LacZ;
DE            Short=Beta-gal {ECO:0000250|UniProtKB:P19668};
DE            EC=3.2.1.23;
GN   Name=lacZ {ECO:0000312|EMBL:AAV43283.1}; OrderedLocusNames=LBA1462;
OS   Lactobacillus acidophilus (strain ATCC 700396 / NCK56 / N2 / NCFM).
OC   Bacteria; Bacillota; Bacilli; Lactobacillales; Lactobacillaceae;
OC   Lactobacillus.
OX   NCBI_TaxID=272621;
RN   [1] {ECO:0000305, ECO:0000312|EMBL:ACC38288.1}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND BIOTECHNOLOGY.
RC   STRAIN=ATCC 4356 / DSM 20079 / NBRC 13951 / JCM 1132 / NCIMB 8690;
RX   PubMed=19841976; DOI=10.1007/s00284-009-9521-9;
RA   Pan Q., Zhu J., Liu L., Cong Y., Hu F., Li J., Yu X.;
RT   "Functional identification of a putative beta-galactosidase gene in the
RT   special lac gene cluster of Lactobacillus acidophilus.";
RL   Curr. Microbiol. 60:172-178(2010).
RN   [2] {ECO:0000312|EMBL:AAV43283.1}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 700396 / NCK56 / N2 / NCFM;
RX   PubMed=15671160; DOI=10.1073/pnas.0409188102;
RA   Altermann E., Russell W.M., Azcarate-Peril M.A., Barrangou R., Buck B.L.,
RA   McAuliffe O., Souther N., Dobson A., Duong T., Callanan M., Lick S.,
RA   Hamrick A., Cano R., Klaenhammer T.R.;
RT   "Complete genome sequence of the probiotic lactic acid bacterium
RT   Lactobacillus acidophilus NCFM.";
RL   Proc. Natl. Acad. Sci. U.S.A. 102:3906-3912(2005).
CC   -!- FUNCTION: Catalyzes the hydrolysis of lactose to its constituent
CC       monosaccharides glucose and galactose. {ECO:0000269|PubMed:19841976}.
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         Evidence={ECO:0000269|PubMed:19841976};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=3.84 mM for o-nitrophenyl-beta-D-galactopyranoside (ONPG) (at 37
CC         degrees Celsius and pH 6.0) {ECO:0000269|PubMed:19841976};
CC         KM=88.9 mM for lactose (at 37 degrees Celsius and pH 6.0)
CC         {ECO:0000269|PubMed:19841976};
CC       pH dependence:
CC         Optimum pH is 6.0 for both lactose and ONPG hydrolysis, but lactose
CC         hydrolysis activity is more sensitive to changes in pH than ONPG
CC         hydrolysis activity. {ECO:0000269|PubMed:19841976};
CC       Temperature dependence:
CC         Optimum temperature is 37 degrees Celsius for both lactose and ONPG
CC         hydrolysis. Retains 16.5% of activity for ONPG hydrolysis and 11.2%
CC         of activity for lactose hydrolysis at 4 degrees Celsius. Stable at or
CC         below 25 degrees Celsius, but loses 50% of its activity after 1 hour
CC         at 37 degrees Celsius and is inactivated after only 40 minutes at 45
CC         degrees Celsius. Can hydrolyze 73% of lactose in milk in 30 hours at
CC         10 degrees Celsius. {ECO:0000269|PubMed:19841976};
CC   -!- BIOTECHNOLOGY: Has potential for lactose removal from dairy products at
CC       refrigerated temperatures. {ECO:0000269|PubMed:19841976}.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 42 family. {ECO:0000255}.
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DR   EMBL; EU590652; ACC38288.1; -; Genomic_DNA.
DR   EMBL; CP000033; AAV43283.1; -; Genomic_DNA.
DR   RefSeq; WP_011254470.1; NC_006814.3.
DR   RefSeq; YP_194314.1; NC_006814.3.
DR   AlphaFoldDB; Q5FJ41; -.
DR   SMR; Q5FJ41; -.
DR   STRING; 272621.LBA1462; -.
DR   CAZy; GH42; Glycoside Hydrolase Family 42.
DR   GeneID; 56943037; -.
DR   KEGG; lac:LBA1462; -.
DR   PATRIC; fig|272621.13.peg.1384; -.
DR   eggNOG; COG1874; Bacteria.
DR   HOGENOM; CLU_012430_1_1_9; -.
DR   OrthoDB; 9800974at2; -.
DR   BioCyc; LACI272621:G1G49-1432-MONOMER; -.
DR   Proteomes; UP000006381; Chromosome.
DR   GO; GO:0009341; C:beta-galactosidase complex; IEA:InterPro.
DR   GO; GO:0004565; F:beta-galactosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0006012; P:galactose metabolic process; IEA:InterPro.
DR   CDD; cd03143; A4_beta-galactosidase_middle_domain; 1.
DR   Gene3D; 3.40.50.880; -; 1.
DR   Gene3D; 3.20.20.80; Glycosidases; 1.
DR   Gene3D; 2.60.40.1180; Golgi alpha-mannosidase II; 1.
DR   InterPro; IPR013739; Beta_galactosidase_C.
DR   InterPro; IPR013738; Beta_galactosidase_Trimer.
DR   InterPro; IPR029062; Class_I_gatase-like.
DR   InterPro; IPR003476; Glyco_hydro_42.
DR   InterPro; IPR013529; Glyco_hydro_42_N.
DR   InterPro; IPR013780; Glyco_hydro_b.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   PANTHER; PTHR36447; BETA-GALACTOSIDASE GANA; 1.
DR   PANTHER; PTHR36447:SF1; BETA-GALACTOSIDASE GANA; 1.
DR   Pfam; PF02449; Glyco_hydro_42; 1.
DR   Pfam; PF08533; Glyco_hydro_42C; 1.
DR   Pfam; PF08532; Glyco_hydro_42M; 1.
DR   PIRSF; PIRSF001084; B-galactosidase; 1.
DR   SUPFAM; SSF51445; (Trans)glycosidases; 1.
DR   SUPFAM; SSF52317; Class I glutamine amidotransferase-like; 1.
PE   1: Evidence at protein level;
KW   Glycosidase; Hydrolase; Metal-binding; Reference proteome; Zinc.
FT   CHAIN           1..667
FT                   /note="Beta-galactosidase LacZ"
FT                   /id="PRO_0000407690"
FT   ACT_SITE        148
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   ACT_SITE        307
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         109
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         113
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         147
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         153
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         155
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         158
FT                   /ligand="Zn(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29105"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         315
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         355..358
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
SQ   SEQUENCE   667 AA;  76584 MW;  0034A0EC1C4438D2 CRC64;
     MTQLSRFLYG GDYNPDQWPE ETWSKDIHVF KKADINSATI NIFSWALLEP REGKYNFSKL
     DKVVQQLSDA NFDIVMGTAT AAMPAWMFKK YPDIARVDYQ DRRHVFGQRH NFCPNSSNYQ
     RLAGELVKQL VERYKDNKHI VVWHINNEYG GNCYCENCQN AFRKWLKNKY KTVEGLNKAW
     NMNVWSHTIY DWDEIVVPNE LGDVWGIEGS ETIVAGLSID YLRFQSESMQ NLFKMEKKII
     KKYDPETPVT TNFHGLPNKM VDYQKWAKGQ DIISYDSYPT YDAPAYKAAF LYDLMRSLKH
     QPFMLMESAP SQVNWQPYSP LKRPGQMEAT EFQAVAHGAD TVQFFQLKQA VGGSEKFHSA
     VIAHSQRTDT RVFKELADLG KKLKNAGPTI LGSKTKAKVA IVFDWSNFWS YEYVDGITQD
     LNYVDSILDY YRQFYERNIP TDIIGVDDDF SNYDLVVAPV LYMVKHGLDK KINDYVENGG
     NFVTTYMSGM VNSSDNVYLG GYPGPLKEVT GIWVEESDAV VPGQKIKVLM NGKDYDTGLI
     CNLIHPNDAK ILATYASEFY AGTPAVTENQ YGKGRAWYIG TRLEHQGLTQ LFNHIIFETG
     VESLVCDSHK LEITKRVTED GKELYFVLNM SNEERTLPSK FTGYEDILTG EKAHKDMKGW
     DVQVLRN
//