Enzyme - Beta-galactosidase

Alternative Name(s)
  • Exo-(1->4)-beta-D-galactanase.
  • Lactase.

Catalytic Activity

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


There are no Cofactors for this Enzyme

Reaction Mechanism

    Catalyses the hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactoside. Belongs to the glycosyl hydrolase 2 family.

    Glu537 initiates a nucleophilic attack on the substrate, which eliminates the first product. Glu461 activates the catalytic water, which attacks the enzyme-substrate adduct, eliminating the final product and returning the enzyme to its native state.
    Catalytic Residues
    AA Uniprot Uniprot Resid PDB PDB Resid
    His P00722 358 4v40 357
    Glu P00722 462 4v40 461
    Glu P00722 538 4v40 537
    His P00722 392 4v40 391
    Glu P00722 417 4v40 416
    Asp P00722 202 4v40 201
    His P00722 419 4v40 418
    Phe P00722 602 4v40 601
    Asn P00722 605 4v40 604
    Asn P00722 598 4v40 597

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Protein name Organism
Beta-galactosidase 7 Mouse-ear cress
Beta-galactosidase A Aspergillus niger (strain CBS 513.88 / FGSC A1513)
Beta-galactosidase 17 Mouse-ear cress
Beta-galactosidase small subunit Lactobacillus acidophilus (strain ATCC 700396 / NCK56 / N2 / NCFM)
Beta-galactosidase 3 Mouse-ear cress