β− galactosidase is a structural gene present in segment of DNA, which carry Icdes for the synthesis of protein. Mutation in the /ac Ygene of E.coli needs residues of ytoplasmic enzyme β− galactosidase. Lactose permease is a membrane protein, which is a major facilitator superfamily. Transacetylase is an enzyme transferring acetyl groups from one compound to another.