Disease relevance of melibiose

• Trp-999 of beta-galactosidase (Escherichia coli) is a key residue for binding, catalysis, and synthesis of allolactose, the natural lac operon inducer [1].

High impact information on melibiose

• The resulting restricted access to the intermediate helps to explain why allolactose, the natural inducer for the lac operon, is the preferred product of transglycosylation [2].
• The transfer products from galactosyl-ebgabcd and galactosyl-ebgabcde to high concentrations to glucose have been measured; the predominant product is allolactose, but significant quantities of lactose are also formed; however, at apparent kinetic saturation of the galactosyl-enzyme, hydrolysis rather than transfer is the preponderant pathway [3].

Associations of melibiose with other chemical compounds

• Transgalactosylation activity of ebg beta-galactosidase synthesizes allolactose from lactose [4].
• An important finding relating to the role of allolactose as an inducer of the lac operon was that allolactose (beta-D-galactosyl-(1----6)-D-glucose) was the only disaccharide formed initially, and at equilibrium it was present in the largest amount (50%) [5].

Gene context of melibiose

• The action of beta-galactosidase (Escherichia coli) on allolactose [6].

References