Many plasmid vectors (e.g., the pUC collection, Bluescript, pGem, and their derivatives) carry a brief phase of Escherichia coli DNA containing the regulatory sequences and the coding data for the primary 146 amino acids of β-galactosidase. Vectors of this kind are utilized in host cells that specific the carboxy-terminal portion of β-galactosidase. Though neither the host-encoded fragments nor the plasmid-encoded fragments […]