6-phospho-beta-galactosidase (EC:3.2.1.85) is part of the tagatose-6-phosphate pathway of galactose-6-phosphate degradation.
A 6-phospho-beta-D-galactoside + H2O = an alcohol + 6-phospho-D-galactose
The genes coding for the enzymes of the tagatose 6-phosphate pathway have been found to be part of the lac operon together with the
genes coding for the lactose-phosphotransferase system and the phospho-beta-galactosidase in Lactococcus lactis, Staphylococcus aureus, and Streptococcus mutans.