ID   BGAL1_ARTSP             Reviewed;         690 AA.
AC   Q44233;
DT   03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT   03-MAY-2011, sequence version 2.
DT   03-AUG-2022, entry version 66.
DE   RecName: Full=Beta-galactosidase;
DE            Short=Beta-gal {ECO:0000250|UniProtKB:P19668};
DE            EC=3.2.1.23;
OS   Arthrobacter sp.
OC   Bacteria; Actinobacteria; Micrococcales; Micrococcaceae; Arthrobacter.
OX   NCBI_TaxID=1667;
RN   [1] {ECO:0000305, ECO:0000312|EMBL:AAA75601.1}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 9-16, FUNCTION,
RP   CATALYTIC ACTIVITY, ACTIVITY REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, AND
RP   SUBSTRATE SPECIFICITY.
RC   STRAIN=B7 {ECO:0000269|PubMed:7721689};
RX   PubMed=7721689; DOI=10.1128/jb.177.8.1981-1988.1995;
RA   Gutshall K.R., Trimbur D.E., Kasmir J.J., Brenchley J.E.;
RT   "Analysis of a novel gene and beta-galactosidase isozyme from a
RT   psychrotrophic Arthrobacter isolate.";
RL   J. Bacteriol. 177:1981-1988(1995).
CC   -!- FUNCTION: Highly specific towards beta-D-galactoside substrates.
CC       Hydrolyzes 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal)
CC       and o-nitrophenyl-beta-D-galactopyranoside (ONPG). Has activity against
CC       p-nitrophenyl(pNP)-beta-D-galactoside, but not significantly at all
CC       towards pNP-alpha-D-galactoside, pNP-beta-D-glucoside, pNP-beta-D-
CC       mannoside, pNP-beta-L-fucoside, pNP-beta-D-xyloside, pNP-beta-L-
CC       arabinoside, pNP-beta-D-galuronide, pNP-beta-D-glucuronide, pNP-beta-D-
CC       lactoside or pNP-beta-D-cellobioside. {ECO:0000269|PubMed:7721689}.
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:7721689};
CC   -!- ACTIVITY REGULATION: Activity stimulated by beta-mercaptoethanol.
CC       {ECO:0000269|PubMed:7721689}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=0.57 mM for ONPG {ECO:0000269|PubMed:7721689};
CC         KM=4.81 mM for lactose {ECO:0000269|PubMed:7721689};
CC         Vmax=254 umol/min/mg enzyme with ONPG as substrate
CC         {ECO:0000269|PubMed:7721689};
CC         Vmax=3.97 umol/min/mg enzyme with lactose as substrate
CC         {ECO:0000269|PubMed:7721689};
CC       pH dependence:
CC         Optimum pH is 6.6. Maintains activity over a broad range of pH values
CC         from 6 to 9. {ECO:0000269|PubMed:7721689};
CC       Temperature dependence:
CC         Optimum temperature is 45-50 degrees Celsius. Activity declines
CC         rapidly above 50 degrees Celsius. Stable for at least 70 hours at
CC         temperatures 35 degrees Celsius and below. At 50 degrees Celsius
CC         loses all activity in less than 15 minutes.
CC         {ECO:0000269|PubMed:7721689};
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 42 family. {ECO:0000255}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAA75601.1; Type=Frameshift; Evidence={ECO:0000305};
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DR   EMBL; U17417; AAA75601.1; ALT_FRAME; Genomic_DNA.
DR   AlphaFoldDB; Q44233; -.
DR   SMR; Q44233; -.
DR   CAZy; GH42; Glycoside Hydrolase Family 42.
DR   GO; GO:0009341; C:beta-galactosidase complex; IEA:InterPro.
DR   GO; GO:0004565; F:beta-galactosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006012; P:galactose metabolic process; IEA:InterPro.
DR   Gene3D; 2.60.40.1180; -; 1.
DR   Gene3D; 3.40.50.880; -; 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; PTHR36447; 2.
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; SSF51445; 1.
DR   SUPFAM; SSF52317; SSF52317; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Glycosidase; Hydrolase.
FT   CHAIN           1..690
FT                   /note="Beta-galactosidase"
FT                   /id="PRO_0000407680"
FT   ACT_SITE        174
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         173
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
FT   BINDING         345
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:O69315"
SQ   SEQUENCE   690 AA;  76115 MW;  83262445ECE19128 CRC64;
     MPVPTPLSEG TTPDTAAQEL RTNRLWEALP GLSYGGDYIP NSGRNRSARK IYRSCRKPEC
     RPSALASSPG LGLEPVEGSY DFTWLDEVMD NLAATGIKVA LATATAAPPA GWLRKHPEIL
     PVTAEGSTLG PARAHYLVVG MVLFCRPVCG EDDPRLGERY KDHPALALWH VDNELGCHVS
     EFYGPRRHRR FPSMAEPTLR HDRGPQRGLG TAFWSQRYSC FEEILTPRPA PTTLNPTQQL
     DFQRFSSWGL IDFYSMLARG HFARSHPRCP PRQIWWPQAP PCLWDYFDWA KKLECHRQWS
     LPGGRRYRCV TSELAFRRRS DSEAIAGGKP WSPDGALSPC RPCNWLASQH DSRTPGEMAR
     NSLVHVGRGI WMLSCFSSGD RASRVRRNST RPWCRTPEPT REYGVKLLSW AQAQSLVRGS
     RRRGGITHRN RLRLRTLVGK RTGLHPAPMW KYLELLRAFH APCSCPASPP IWSIPALTLT
     AMTWWSSRPC TPSPMPRPAI LRQRQNAEPQ CSSATSVDID ENDAVRLGGY PGAFRDLLGV
     NVEEFHPLPE NSTVSLDAGW SGRIWSEHVH LTGAEAKVSF TEAPLTGVPA VTRHAVGTGA
     AWYLATFPDA TGLESLLDSL IAESGVRAPA MAAAGVELSR RSHADGRSYL FAINHNVTEA
     AVSAQGTELI SGTPFNGTVP AGAVAVIAEG