Abstract
The lac thiogalactoside transacetylase was purified from both a wild-type E. coli K-12 strain (H3000) and an E. coli ML strain (ML308). These enzymes are distinguishable by using several criteria. The subunit MW of the enzyme is 24,800, which is significantly less than the previously reported value of 30,000. Although the function of the thiogalactoside transacetylase is unknown, this enzyme plays an important role in lactose utilization since its structure and enzymatic activity were conserved.