ExPASy Proteomics Server

Accession	MF_01687
Dates	19-FEB-2009 (Created) 25-NOV-2009 (Last updated, Version 5)

Data class

Protein

Predictors

HAMAP; MF_01687; [distribution of match scores in UniProtKB];[seed alignment for MF_01687]

Names

Beta_gal

Identifier

BGAL

Protein name

RecName: Full=Beta-galactosidase; Short=Beta-gal; EC=3.2.1.23; AltName: Full=Lactase;

Gene name

lacZ

CATALYTIC ACTIVITY: Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides.

COFACTOR: Binds 2 magnesium ions per monomer (By similarity).

COFACTOR: Binds 1 sodium ion per monomer (By similarity).

SUBUNIT: Homotetramer (By similarity).

SIMILARITY: Belongs to the glycosyl hydrolase 2 family.

PROSITE	PS00719; GLYCOSYL_HYDROL_F2_1; 1; PS00608; GLYCOSYL_HYDROL_F2_2; 1;
Pfam	PF02929; Bgal_small_N; 1; PF00703; Glyco_hydro_2; 1; PF02836; Glyco_hydro_2_C; 1; PF02837; Glyco_hydro_2_N; 1;
PRINTS	PR00132; GLHYDRLASE2; 1;

Glycosidase, Hydrolase, Magnesium, Metal-binding, Sodium.

GO:0000287; Molecular function: magnesium ion binding.
GO:0016798; Molecular function: hydrolase activity, acting on glycosyl bonds.

From: BGAL_ECOLI (P00722)
Key		From		To		Description		Condition		FTGroup
REGION		538		541		Substrate binding (By similarity)		E-Y-A-H
ACT_SITE		462		462		Proton donor (By similarity)		E
ACT_SITE		538		538		Nucleophile (By similarity)		E
METAL		202		202		Sodium (By similarity)		D
METAL		417		417		Magnesium 1 (By similarity)		E
METAL		419		419		Magnesium 1 (By similarity)		H
METAL		462		462		Magnesium 1 (By similarity)		E
METAL		598		598		Magnesium 2 (By similarity)		N
METAL		602		602		Sodium; via carbonyl oxygen (By similarity)		F
METAL		605		605		Sodium (By similarity)		[DN]
BINDING		103		103		Substrate (By similarity)		N
BINDING		202		202		Substrate (By similarity)		D
BINDING		462		462		Substrate (By similarity)		E
BINDING		605		605		Substrate (By similarity)		[DN]
BINDING		1000		1000		Substrate (By similarity)		W
SITE		358		358		Transition state stabilizer (By similarity)		H
SITE		392		392		Transition state stabilizer (By similarity)		H

Size range:	1020-1066 amino acids
Related UniRules:	None
Template:	P00722 (BGAL_ECOLI); A3FEW8 (BGAL_ENTAG); P81650 (BGAL_PSEHA): [Recover all]
Scope:	Bacteria
Fusion:	Nter: None; Cter: None
Duplicate:	in ENTCL, KLEP7, KLEPN
Plasmid encoded:	in ECOLX, KLEP7, KLEPN
Comments:	ENTAG, and maybe other bacteria, are able to transfer a glycosyl to the hydroxyl groups of a series of accecptors including hexose, pentose, disaccharides, hexahydroxy alcohol, cyclitol, and aromatic glycosides.