Beta-galactosidase (B-galactosidase), also known as lactase, is encoded by the lacZ gene that is commonly found in the plasmid of the bacterium E. coli. This gene resides within the lac operon, regulated by the lac repressor and CAP. B-galactosidase is an enzyme that catalyses the hydrolysis of a disaccharide, lactose, into the two monosaccharides, glucose and galactose.
Notably, the lacZ gene is one of the regularly utilised reporter genes in Reporter Gene Assays. This enables the measurement of the activity of the gene of interest through the production of blue pigment resulting from the hydrolysis of X-gal by Beta-galactosidase (see blue/white selection technique).
- ↑ Alberts. A, Johnson. A, Lewis. J, Morgan. D, Raff. M, Roberts. K, et al. Molecular Biology of the Cell. 6th ed. New York: Garland Science. 2015.
- ↑ ThermoFisher Scientific. Reporter Gene Assays. 2016 [cited 20/3/18]; Available from: https://www.thermofisher.com/uk/en/home/references/gibco-cell-culture-basics/transfection-basics/reporter-gene-assays.html