Expression of enzymatically active reverse transcriptase in Escherichia coli.

Reverse transcriptase of murine retroviruses is a monomeric protein of approximately 80,000 daltons, which is encoded by the central portion of the viral pol gene. To prepare large quantities of the enzyme, we have constructed gene fusions between the trpE gene and portions of the pol gene of Moloney murine leukemia virus. The inserted pol gene sequences include the entire coding region for the mature enzyme and various amounts of additional coding sequences. Many of these constructs express high levels of reverse transcriptase activity even though the NH2 and COOH termini of the protein product only approximate the correct termini of the authentic protein.