UniProt functional annotation for P00722



	UniProt functional annotation for P00722

UniProt code: P00722.

Organism: Escherichia coli (strain K12).

Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.

Catalytic activity: Reaction=Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides.; EC=3.2.1.23;

Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Note=Binds 2 magnesium ions per monomer. Can also use manganese.;

Cofactor: Name=Na(+); Xref=ChEBI:CHEBI:29101; Note=Binds 1 sodium ion per monomer.;

Activity regulation: Inhibited by phenylethyl thio-beta-D-galactoside (PETG), isopropyl thio-beta-D-galactoside (IPTG), L-ribose, D- galactonolactone, lactose and 2-amino-D-galactose. {ECO:0000269|PubMed:14621996}.

Biophysicochemical properties: Kinetic parameters: KM=0.04 mM for p-nitrophenyl beta-D-galactoside {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=0.12 mM for o-nitrophenyl beta-D-galactoside {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=0.15 mM for 2,3-dinitrophenyl beta-D-galactopyranoside {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=0.41 mM for 2,5-dinitrophenyl beta-D-galactopyranoside {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=11.6 mM for p-nitrophenol-alpha-L-arabinopyranoside {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=16.9 mM for p-nitrophenol-beta-D-fucopyranoside {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=34 uM for p-nitrophenyl beta-D-galactoside (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=140 uM for o-nitrophenyl beta-D-galactoside (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=940 uM for allolactose (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; KM=1350 uM for lactose (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; Vmax=30.9 umol/min/mg enzyme with lactose as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; Vmax=49.7 umol/min/mg enzyme with allolactose as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; Vmax=59.7 umol/min/mg enzyme with p-nitrophenyl beta-D-galactoside as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; Vmax=360 umol/min/mg enzyme with o-nitrophenyl beta-D-galactoside as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269|PubMed:114210, ECO:0000269|PubMed:12578395, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:15060622, ECO:0000269|PubMed:8662937, ECO:0000269|PubMed:9665715}; Note=The values for the enzymatic assays using manganese as cofactor are very close.;

Subunit: Homotetramer. {ECO:0000269|PubMed:11045615, ECO:0000269|PubMed:11732897, ECO:0000269|PubMed:14621996, ECO:0000269|PubMed:8008071}.

Induction: By allolactose. {ECO:0000269|PubMed:4562709}.

Similarity: Belongs to the glycosyl hydrolase 2 family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Escherichia coli (strain K12).
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.


Catalytic activity:		Reaction=Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides.; EC=3.2.1.23;
Cofactor:		Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Note=Binds 2 magnesium ions per monomer. Can also use manganese.;
Cofactor:		Name=Na(+); Xref=ChEBI:CHEBI:29101; Note=Binds 1 sodium ion per monomer.;
Activity regulation:		Inhibited by phenylethyl thio-beta-D-galactoside (PETG), isopropyl thio-beta-D-galactoside (IPTG), L-ribose, D- galactonolactone, lactose and 2-amino-D-galactose. {ECO:0000269\|PubMed:14621996}.
Biophysicochemical properties:		Kinetic parameters: KM=0.04 mM for p-nitrophenyl beta-D-galactoside {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=0.12 mM for o-nitrophenyl beta-D-galactoside {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=0.15 mM for 2,3-dinitrophenyl beta-D-galactopyranoside {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=0.41 mM for 2,5-dinitrophenyl beta-D-galactopyranoside {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=11.6 mM for p-nitrophenol-alpha-L-arabinopyranoside {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=16.9 mM for p-nitrophenol-beta-D-fucopyranoside {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=34 uM for p-nitrophenyl beta-D-galactoside (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=140 uM for o-nitrophenyl beta-D-galactoside (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=940 uM for allolactose (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; KM=1350 uM for lactose (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; Vmax=30.9 umol/min/mg enzyme with lactose as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; Vmax=49.7 umol/min/mg enzyme with allolactose as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; Vmax=59.7 umol/min/mg enzyme with p-nitrophenyl beta-D-galactoside as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; Vmax=360 umol/min/mg enzyme with o-nitrophenyl beta-D-galactoside as substrate (with magnesium as cofactor and 30 degrees Celsius) {ECO:0000269\|PubMed:114210, ECO:0000269\|PubMed:12578395, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:15060622, ECO:0000269\|PubMed:8662937, ECO:0000269\|PubMed:9665715}; Note=The values for the enzymatic assays using manganese as cofactor are very close.;
Subunit:		Homotetramer. {ECO:0000269\|PubMed:11045615, ECO:0000269\|PubMed:11732897, ECO:0000269\|PubMed:14621996, ECO:0000269\|PubMed:8008071}.
Induction:		By allolactose. {ECO:0000269\|PubMed:4562709}.
Similarity:		Belongs to the glycosyl hydrolase 2 family. {ECO:0000305}.